B.

One eye.

Thorax divided into many segments, as in Condylura. The anterior and much the largest segment presents a single eye only placed in the middle of the front between the superior antennæ. Cyclops (Müller), which has been so well illustrated by the acute observations of the elder Jurine and of Ramdohr, is the only genus of this subdivision.

about fifteen days in the months of February or March) they acquire another pair of feet; they are then the genus Nauplius of the same author. After their first moult they assume the form and all the parts which characterize the adult state, but with smaller proportions: their antennas and feet, for example, are comparatively short. At the end of two more moults they are fit for the reproduction of the species. The greater part of these entomostraca swim upon their backs, darting about with vivacity, and possessing the power of moving either backwards or forwards, Their food generally consists of animal matter in preference to vegetable; but in the absence of the former they feed on substances of the latter description, and it is said that the fluid in which they live never enters their stomachs. The alimentary canal extends from one extremity of the body to the other. The heart (taking Cyclops Castor as the subject) is of a shape approaching to oval, and situated immediately under the second and third segment of the body. Each of the extremities of this organ gives off a vessel, the one going to the head, the other to the tail. Immediately below is another analogous organ, giving off also at each end a vessel supposed to represent the branchiocardiac canals observable in the circulation of the Decapod Crustaceans. Jurine, who on many occasions reduced the Cylife, found that in the process of reanimation the extremity of the intestinal canal and the supports gave the first signs of approaching animation, while the irritability of the heart was less energetic, and that of the antennæ, especially in the males, of the feelers and of the feet still inferior. When a portion of an antenna is cut off no change is effected at the time, but the organ is entirely restored in the succeeding moult. There are differences in the form of the antennæ and body of Cyclops Staphylinus, and in the kind of horny process arising on the under part of its tail and curved backwards, which led Latreille to consider it as forming a distinct subdivision; and he seems to be of opinion that Cyclops Castor and some others, whose lower antennæ and mandibulary feelers are divided, beyond their base, into two branches, may form another group. Calanus (Leach), he observes, may be a sub-genus, if it be true that the animal which forms the type has no inferior antennæ; but he seems to doubt whether this absence was made out by Leach's own observations, or whether the assertion is made on the authority of Müller.

The body of the Cyclopes is more or less approaching to oval, soft or rather gelatinous, and is divided into two portions. the one anterior, consisting of the head and thorax, the other posterior, forming what is commonly called the tail. The segment immediately preceding the sexual organs, and which in the females carries two supporting appendages in the form of little feet (fulcra, Jurine), may be considered as the first segment of the tail, which is not always very clearly defined or strongly distinguished from the thorax, and consists of six segments or joints, the second of which in the males is provided on its lower side with two articulated appendages of varied form, sometimes simple. sometimes having a small division at the internal edge, and constituting entirely or in part the organs of generation. In the other sex the female organ is placed upon the same joint. The last segment terminates in two points forming a fork, and more or less bordered with delicate beards or penniform fringes.clopes to a state of complete asphyxia and restored them to The anterior portion of the body is divided into four segments, of which the first and by far the largest includes the head and a portion of the thorax, which are thus covered by one scale common to both. Here are situated the eye, four antennæ, two mandibles (internal mandibles of Jurine) furnished with a feeler (which is either simple or divided into two articulated branches), two jaws (the external mandibles or lip with little beards of Jurine), and four feet divided each into two cylindrical stems, fringed with hairs or bearded. The anterior pair representing the second pair of jaws differ a little from the succeeding pair, and are compared by Jurine to a kind of hands. Each of the three succeeding segments serves as the point of attachment to a pair of feet. The two superior antennæ are longest, setaceous, simple, and formed of a great number of small articulations. They facilitate by their action the motion of the body, and perform very nearly the office of feet. The lower antennæ (antennules of Jurine) are filiform, consisting most frequently of not more than four joints, and are sometimes simple, sometimes forked. By their rapid motion they produce a small eddy in the water. In the males the upper antennæ, or one of them only, as in Cyclops Custor, are contracted in parts, and exhibit a swelling portion which is followed by a hinge joint. By means of these organs, or of one of them, the males seize either the hind feet or the end of the tail of their females in their amorous approaches: when these last are unwilling they carry the males about for some time. The copulation is prompt and reiterated. Jurine saw three acts in a quarter of an hour. Before his time, it was generally believed that the male organs were situated at the upper antennæ, an error which was supported by the analogy of those of the aruneids. On each side of the tail of the females is an oval bag filled with eggs (external ovary of Jurine), adhering by a very fine pedicle to the second segment, near its junction with the third, and where the orifice of the deferent egg canal may be seen. The pellicle which forms these bags is only a continuation of that of the internal ovary. The number of contained eggs increases with age. They are at first brown or obscure, but afterwards present a reddish tinge and become nearly transparent, without however increasing in size, when the young are about to come forth. When isolated or detached, up to a certain period at least, the germ perishes. A single fecundation, which is indispensable, suffices for successive generations, and the same female can lay eggs ten times in the course of three months, so that the number of births amounts to something enormous*. The time for the fœtus to remain in the ovary varies from two to ten days, the variation depending on the temperature of the seasons and on other circumstances. The oviparous bags present sometimes elongated, glandiform bodies, more or less numerous, which are supposed to be congregations of infusory animalcules.

The young at their birth have only four feet, and their body is rounded and tailless. In this state they are the genus Amymone of Müller. Some time afterwards (in

Taking eight ovipositions and allowing forty eggs for each, it has been calculated that one female Cyclops may be the progenitress of four thousand

five hundred millions.

The genus Cyclops is an inhabitant of the fresh waters; and we select the common Cyclops, Cyclops vulgaris, Leach; Monoculus quadricornis, Linn.; Cyclops quadricornis, Müller; Monocle à queue fourchue, Geoffroy, as an example of the species.

The body of the common Cyclops has a somewhat swollen appearance and is formed of four rings, and prolonged to about one-third of its entire length. The tail consists of seven rings. The posterior antennæ (antennules of Jurine) are tolerably large and composed of four joints, the anterior antennæ are thrice the length of the posterior. There are several varieties.

Var. a. Reddish; eggs brown, forming two oblique masses near the sides of the tail. Total length eighttwelfths of a line. This is the Monoculus quadricornis rubens of Jurine.

Var. b. Whitish or grey, somewhat tinged with brown, rather larger than the preceding. Egg-masses greenish, forming nearly a right angle with the tail. Total length the same as the preceding. This is the Mon. quadr. albidus of Jurine.

Var. c. Greenish. Direction of the two egg-masses intermediate between that of the egg-masses of the two former. Length nine-twelfths of a line. Mon. quadr. viridis of Jurine.

Var. d. Smoky red. General form nearly oval. Eggs brown composing two masses, which cover a great portion of the tail. Length six-twelfths of a line. Mon. quadr. fuscus of Jurine.

Var. e. Of a deeper green than Var. c. Eggs obscure green, passing a little into rose-colour when hatching is near, forming two masses attached to the tail, and appearing to be incorporate with it. Length the same as the preceding. Mon. quadr. prasinus of Jurine.

According to Jurine's observations, the common Cyclops four feet only and but two antennæ. In this state it conwhen hatched is nearly spherical, and is furnished with tinues till the fifteenth day, and then a small elongation

times between that day and the 18th of May following. On, the 27th of the last-named month she laid again, and, two days afterwards, made a second deposit. Jurine concludes that the number of moults in the young state corresponds with the gradual development of the individual. Desmarest considers that they do not undergo a metamorphosis, but that they present, on their exclusion from the egg, the form which they preserve throughout their life. Their food is said to consist of dead animal substances and of conferva. In summer, when the heats have dried up the pools, they plunge into the humid mud, and there remain in an apocryphal kind of existence till the rains again restore them to activity.

The recent species are numerous; Jurine describes twenty one. Of these we select the largest, Cypris ornata (one line and 2-12ths), Müller, for an external view, and Cypris fusca (of a millimetre), Straus, to show the internal organization.

B

BRA

latter sort, which are most remarkable, are shown, &c. these are of the genus Cyclops. May not Baker have had Cypris in his eye when he wrote 'testaceous animalculesfor when the valves are closed, it has all the appearance of an acephalous testaceous mollusk in a bivalve shell-and may not this be the passage alluded to by Bennet? The following authors may be consulted on these animals, whose highly curious organization and history have employed the pens of Linnæus, Joblot, Geoffroi, Müller, Ledermüller, Bennet, De Geer, Fabricius, Bosc, Cuvier, Latreille, Daudebart, De Férussac, Lamarck, Straus, Jurine, Desmarest.

***

Cladócera, Latreille; Daphnides, Straus. These, which are very minute, have a single eye only, and are protected by a shell doubled as it were, but without any hinge, according to Jurine, and terminated posteriorly in a point. The head, which is covered with a kind of beaklike armour, projects beyond the shell. There are two antennæ, generally large, in the form of arms, divided into two or three branches, placed on a peduncle fringed with filaments always projecting, and serving the purpose of oars. The feet are ten in number, terminated by a digitated or pectinated swimming organ, and furnished, with the exception of the two first, with a branchial lamina. Their eggs are situated on the back, and their body terminates with a sort of tail, with two delicate hairs or filaments at the end. The anterior part of the body is sometimes prolonged into the form of a beak, sometimes into a shape approaching that of a head occupied nearly entirely by one large eye.

Latreille gives the following subgenera: Polyphemus, Müller; Daphnia, Müller; Lynceus, Müller (Chilodorus, Leach). Of these, Daphnia is the most numerous subgenus, and though it is so extremely small, the observations of naturalists, and more especially of Schoeffer, Ramdohr, Straus, and the elder Jurine, have rendered its organization and habits extremely well known. Straus, who has given Cypris ornata (magnified). Shell yellowish green, banded with green. A, side genera, Latona, characterized by antennæ in the form of an excellent monograph of the Daphnida, adds two sub

view; B. view looking upon the hinge. The bands commence behind the eye. 9

Cypris fusca (magnified), Straus. Valves brown, kidney-shaped, covered with fine scattered hairs. Antennæ with fifteen fine bristles. In the view the valves are supposed to be removed, the outline a a showing their shape and their relative situation; b, origin of the hinge membrane; c, eye; dd, antennæ deprived of their bristles; e feet of the first pair; f, of the second; g, of the third pair; h, tail; i, labrum; k, mandible; 7, feeler; m, jaw of the first pair; n. of the second pair: o, branchia or gill; p 4. posterior portion of the left ovary; r, insertion of the vessel regarded as a testicle by Straus.

FOSSIL CYRIS.

Cypris Fuba, Desmarest, holds a place among the organic remains of the Wealden rocks of England. Dr. Fitton has recorded it in the Weald clay of the Isle of Wight, Swanage Bay. &c., and Mr. Mantell in the Hastings Sands. Desmarest notes the species as found in great abundance near the mountain of Gergovie, in the department of the Puy de Dôme, and at the Balme d' Allier, between Vichyles Bains and Cussac. Their great fruitfulness and the frequent moults noticed above may account in some measure for the quantities of their petrified exuvia. Cypris has also been found in the fresh-water limestone, beneath the Midlothian coal-field, at Burdiehouse, near Edinburgh. Straus observes that Bennet asserts Baker to be the first author who has mentioned this crustaceous form, and that Baker has given a figure of it in the Microscope made Easy,' at plate 15; but Straus adds that neither in the edition of 1743, nor in that of 1744, is any account given of it, and that there is no 15th plate. There certainly is no plate 15 in the edition of 1744, nor any figure or description that will accord with Cypris, while there is, at plate 9, a very fair representation, and at p. 93, a very fair account of Cyclops. Baker commences his account of the latter thus: •We may find in the waters of our ditches several species both of testaceous and crustaceous animalcules, two of these

oars divided into three branches, with a single joint (Daphnia setifera, Müller); and Sida, with antennæ divided into two branches, one of which has but two joints, while the other has three (Daphnia crystallina, Müller). We regret that our limits will not allow us to go into more detail upon these interesting animals, and we must content ourselves with referring to the authors above mentioned, with the addition of Swammerdam, and Latreille, for particulars, observing by the way that one junction of the sexes fecundates the ova for many successive generations, six at least; that their moults are very frequent that they lay at first but one egg, then two or three, and so on progressively as they advance in life till their number amounts to 58 in one species (Daphnia magna); and that the young of the two or three males in a female batch, and vice versa. As same deposit are generally of one sex, it being rare to find the winter approaches, their moults and oviposits cease, and the frost is supposed to destroy them, leaving however the eggs unharmed, which the genial spring season hatches who have microscopes will find ample employment for them. to fill the pools with myriads of Daphnia. Then those Every ditch, every pool, every garden reservoir, will furnish the observer with Branchiopods.

The species are numerous. Water-flea, Monoculus Pulex of Linnæus, Pulex aquaticus The most common is the arborescens of Swammerdam, Le Perroquet d'eau of Geoffroy. Despised as this minute creature may be by those who, like the orientalists, consider size as absolutely neces sary to produce grand ideas, it has fixed the especial attention of Swammerdam, Needham, Leuwenhoek, Schaffer, De Geer, Straus, and above all of Jurine, who, in common interesting information regarding the development of aniwith other philosophers of great name, have found as much mal life in the admirable organization of these animated specks as is afforded by the largest vertebrated animal.

SECTION II.

Phyllopa.

lar or foliaceous form of the joints, representing, according Distinguished by the number of feet, and by the lamelto Latreille, the Myriapods in the class Insects. The eyes sometimes placed on pedicles; many have besides a single are always two in number, formed of a sort of network, and smooth eye.

species confounded under the specific name cancriformis, tral dominions of the reigning family; the Mark itself being viz., Schaffer's and Dr. Leach's, which most resemble indebted for its own denomination to the ancient t. of that Apus Guildingi and that described by Savigny, in which name. Its component parts, however, are not what they the elongated shield entirely covers the natatory members. were in former days; for the N.W. districts of the Electoral Mr. Thompson observes that there is a considerable ap- Mark (Kurmark) and the Alt-mark (Old-m.) have been in proximation between Artemis and certain Trilobites (Bu- corporated with the prov. of Saxony; and the northern parts cephalithus, &c.), nor can there be any doubt that the ana- of the Neumark, adjacent to Pomerania, have been united logies of Branchipus, Serolis and Limulus all contribute to with that prov. In exchange for these, several minor circles, the illustration of that most ancient race of crustaceans. bailiwicks, and other parcels of land, all of them once formWe have not, as yet, data sufficient to fix their proper posi- ing a portion of the districts of Wittemberg, Meissen, Quertion, but there is every reason for supposing that their or- furt, &c., in the kingdom of Saxony, are now comprised in ganization was constructed upon the principle of having the Brandenburg. With the exception of two insignificant same organs made subservient both to locomotion and respi- tracts, surrounded by the territory of Mecklenburg-Schweration. [TRILOBITES.] rin, the prov. forms a compact mass. Its boundaries are, in BRAND or BURN. Brand, a disease in vegetables by the N., the two grand Duchies of Mecklenburg-Schwerin which their leaves and tender bark are partially destroyed and Strelitz, and the Prussian prov. of Pomerania: in the as if they had been burnt; hence the name of this disease, E., the provinces of Western Prussia. Posen, and Silesia: in which is called brûlure in French. It has been observed the S. the provinces of Silesia and Saxony, and the Anhalt that after the leaves have been wetted by dews or gentle principalities; and in the W. the prov. of Saxony, and the rains, so that drops adhere to them, and a bright sunshine Hanoverian dominions. Brandenburg thus extends between has succeeded, every spot to which the water had adhered 51° 10′ and 53° 37′ N. lat. and 11° 13', and 16° 12′ E. long. lost its natural colour, and became of a dark or yellow hue; Its area is about 15,330 sq. m., and occupies about a seventh and on closer examination it was found that the organiza- part of the whole surface of the Prussian dominions; it tion had been partly destroyed, and that these spots no ranks as the fourth prov. with reference to density of pop. longer possessed the power inherent in healthy leaves of The whole of Brandenburg is an almost uninterrupted exhaling water and carbonising the sap which circulates plain, slightly elevated above the surface of the Baltic. Its through them. When this disease is extensive and attacks soil is composed of river sand, in some quarters mingled the bark as well as the leaves, it frequently causes the with ferruginous earth, loam, or clay, and hence arises so death of the plant, and, at all events, enfeebles its growth, great a diversity in its character, that a general failure of and prevents its perfect fructification. The cause of this, crops is almost unknown; for a season unfavourable to one like that of most diseases which are common to plants, has part is usually found proportionably beneficial to another. been vulgarly ascribed to some unknown atmospheric in- The more elevated and undulating parts of the surface, fluence; and various guesses have been made which, for the which are most frequent in the S. districts, between Frankmost part, have little or no foundation. That which ap- fort on the Oder and the Silesian frontier, are improperly peared most plausible was, that the drops of water being called 'mountains by the inhabitants; among these are the apparently globular, collected the light of the sun into a Oderberge (m. of the Oder), the Neiss and Schlagsdorferfocus, and produced a sufficient degree of concentration of berge, in the vicinity of Guben, the Müggelsberge on Lake the calorific rays to burn the tender substance of the leaves. Müggel, about 8 m. S.E. of Berlin, 340 ft. in height, and A little reflection will soon convince us that this will not the heights which run along the Havel. These are probear examination. The drops which adhere to the leaves minent features however in the midst of a wide and weariand the bark are not globes, but at best flattened hemi- some flat, and intermingling with numerous lakes, many of spheres, and consequently cannot collect the rays of the them lying in deep hollows, form landscapes of considerable sun into a focus on the surface to which they adhere; besides, variety. Of the larger class there are not fewer than 131. the spots are as large as the diameter of the drops, so that The most fertile districts are the low lands, termed the all the surface that has been covered with water is injured; Havelland, the Brüche (or Carses) of the Oder, Warth, and whereas the focus of a globe, such as would actually burn Netzel, the Spreewald (wood of the Spree), the N. and E. the leaf, must be very small in proportion to the lens which parts of the Ucker-mark, the Lenzerwische on the Prieg concentrated the rays. It is much more probable that the nitz, and what is denominated the Alte Land' (Old land) effect of the water on the tender epidermis of the leaf or bark in Lower Lusatia. But Brandenburg contains many exto which it adheres is similar to that which it has on vegetable tensive heaths and moors, here called Brennflächen or matter infused in it; it softens and dissolves a portion of it, burning flats), which are a collection of drift sand, the culespecially when the temperature is somewhat raised, and tivation of which has often baffled the utmost efforts of indestroys the vitality; galvanic action may also be excited dustry. The climate of Brandenburg is temperate, but exand increase the effect. It is well known that light is the ceedingly variable: the result of several years' observations great agent which produces the change in the sap circu- fixes the maximum of heat at between 24° and 25° Reaulating in the leaves, and that without light the healthy mur (86° and 88° of Fahrenheit); the maximum of cold is green colour af the leaves and bark, and the peculiar qua- said to be -8° R. (18° below freezing of Fahrenh.), but the lities of the descending sap, are not produced. Little or no temperature is rarely so low as this for more than three or evaporation takes place from the leaves in the night, and four days. It is also stated, that upon a comparison of one the sudden excitement produced on the whole of the surface year with another, there are 210 clear, dry, and 155 damp of the leaves by the rising sun in a clear morning tends to and rainy days. disorganize those parts to which the water adheres. We do not give this as a perfect and adequate solution of the question, but it appears nearer the truth than any of those more commonly received. (De Candolle, Physiologie végétale, vol. iii. chap. iv. s. 2.)

It is a fact that the principal mischief arises from a sudden change of temperature soon after sunrise, especially when there has been a heavy dew or hoar frost in the night; and careful gardeners brush off the drops from their delicate plants before sunrise to guard against the brand. Every drop which falls on the leaves of tender plants from the glass which covers a hotbed in which they grow produces a disease exactly similar to that which we have been describing; and although the vapour of fermenting dung has a pungent, ammoniacal smell, i will be found that the water condensed on the glass is nearly pure, and can have no peculiar corroding effect. It acts therefore simply as a dissolvent, and by stopping the evaporation, which is always rapid from the leaves of plants in a hotbed, produces a derangement in their functions, and ultimately disease. BRAND IN CORN. [BURNT EAR.] BRANDENBURG, a prov. of the kingdom of Prussia, derives its name from the Mark of Brandenburg, the ances

Brandenburg is either traversed or skirted by two of the principal streams of Germany; the Elbe, which forms its N.W. boundary for a short distance, and the Oder, which drains its E. districts. The Elbe skirts Brandenburg only from Sandau to Dömitz, and on this line of its right bank receives the Havel, Stepnitz, and Elde. The number of tracts of land, lower than its surface, which abound in this quarter, are protected from inundation by artificial dykes. The Havel, which is a channel for the efflux of the Böblitz and other small lakes in Mecklenburg-Strelitz, becomes navigable at Fürstenberg, below which point it enters Brandenburg: it then flows past Liebenwalde. Oranienburg and Spandau; and thence taking a W. direction through Potsdam, and the town of Brandenburg, it turns to the N.W. at Plauen, where it is joined by the canal of that name, skirts Rathenow and Havelberg, and falls into the Elbe by two arms, between Havelort and Quitzöbel. It passes through a low tract of country, in which sand, woodlands, and pasture-grounds alternate; its width at Oranienburg is 100 ft., and at Spandau 2000, in consequence of passing through several lakes; below Brandenburg it narrows again to 200, and at its mouth increases to 500. A branch of it strikes off at Brandenburg