May ii, 1 882 J 



NATURE 



43 



The Comparative Action of Isomeric and Meta- 

 meric Compounds on the Growth of Plants. — In an 

 interesting pap;r on this subject, lately laid before the Royal 

 Irish Academy by Prof. Emerson Reynolds, F.R.S., he calls 

 attention to an apparently neglected subject, and he shows that 

 well-marked differences in physiological activity can be detected 

 with the aid of plants, even in cases of metameric bodies of com- 

 paratively si'nple constitution. The bodies he selected for ex- 

 periment were ammonium sulphocyanate and its metamer, theo- 

 carbamide or sulpho-urea. Both compounds are rich in nitrogen, 

 and therefore capable of supplying a highly important element 

 of plant food ; they are easily soluble in water. The experiments 

 were made in (lie summer of l8Si on plants of Nicotiana longi- 

 flora. They lasted over three months— August to end of 

 November; a certain number of the plants were watered with 

 rain-water — a certain number with the compounds in solution, 

 otherwise all the plants were exposed to the like conditions. The 

 following were among the chief results : — 



Total height in inches 



Number of leaves 



Maximum length of leave; in 

 inches 



Maximum breadth ditto 



Number of seed pods 



Ditto well developed ... I ... n ... O 



It would then seem (1) that the particular elements of which a 

 body is composed exert less influence on the physiological activity 

 of the compound than the intra-rnolecular grouping of the com- 

 ponent atoms ; (2) that in some instances at least differences of 

 physiological activity between metameric bodies can be easily 

 detected by the aid of plants. 



Caucasian Milk Ferment. — The inhabitants of the high- 

 lying lands in the Caucasus prepare, by fermentation of cows' 

 milk, a drink which they call kephir. Kephir is used by the 

 inhabitants of the mountains not only as an article of food, but 

 also as a remedy against different diseases. As a ferment in the 

 preparation of this drink, strange white lump; are used, which 

 have a spherical or elliptical shape, and attain the size of from 

 I m. In 5 cm. On a microscopical examina' ion of these lumps, 

 they showed that they consisted of two different substances — 

 yeast cells and bacteria. The yeast cells may be regarded as 

 the ordinary form, produced by cultivation, of Saccharomyces 

 ctreaisia, but Kern was unable to get these to the spore-bearing 

 stage. As to the bacteria, they composed the chief part of the 

 little lumps, and were in the Zoogloei sta'e. The vegetative 

 bacteria cells were 3'2 m. to 8rn. in length, and '8 broad. In pre- 

 parations put up by drying, a distinct cell membrane could be 

 distinguished. Treated after Koch's method, the vegetative cells 

 show at one end a locomotive organ, which resembles a cat-and- 

 nine-tails,.of threads. When exposed to the action of acids or a 

 high temperature, the vegetative-cells grow out [probably through 

 progressive cell-divisions] into long I.eptothrix threads, which 

 change generally precedes the spore-formation stage. The spores 

 are round, always formed in twos in each vegetable cell, and are 

 alway? placed standing on their ends ; even by making use of Hart- 

 nack's immersion X, noparti'ion wall could be dicovered between 

 the spores. In the Leptothrix-threads rows of spores could be 

 observed, which are, however, always so situated that two 

 spores belong to each cell. The spires while still in the cells 

 are - S m. in size ; those lying free attain the size of 1 m. ; the 

 germinating spjres swell up I 6 m. The germination of the 

 spore; generally takes place in such a manner that an exo;porium 

 and an endosporium can always be distingui-hed in them. The 

 thinner endosporium arises out of the thicker exosporium, first as 

 a small excrescence, which gradually increases, developing more 

 and more into a long cylindrical tube, and then begins by cell- 

 division to form vegetative cells. Toe whole course of the 

 development to the spore-formation, beginning with the vege- 

 tative cell to the formation of a similar new cell, was followed. 

 This newly described form of Bacteria, which undoubtedly 

 belongs to the Desmobacteria of Cohn, is in its vegetative state 

 nit unlike the Bacillus subtil is of Cohn ; it is, however, clearly 

 distinguished not only from it, but also from all other kinds of 

 Bacteria hi'herto described by its spore-formation, since it always 

 forms in each cell two round spores place 1 end to end, while in 

 the species of Bacteria hitherto described, only one spore has 

 been noticed in each cell. On account of this sharply-marked 

 feature Kern places this form of Bacteria in a new genus, next to 



the genus Bacillus, and calls it Dispora caucasica, nov. g. et 

 nov. sp. A more exhaustive essay on this subject, with expla- 

 natory plates, Kern promises in the next number of the Bulletin 

 de la Socie'te' Imperial da A'aturalistes de Moscow. — Prof. Dr. J. 

 N. Goroschankin assisted Kern by kindly fumi-hing him with 

 the necessary materials for his work, for which Kern expresses his 

 deepest thanks. — Botanische Zeitung, April 21, 1882, p. 264. 



New Freshwater Sponges.— Mr. Edward Potts describes 

 three more curious freshwater sponges in the Proceedings of the 

 Academy of Natural Sciences of Philadelphia (January 10, 1882 

 p. 12). One found in September, 18S1, near Cbadd's Ford is' 

 of a very delicate structure ; its framework of skeleton spicules 

 is exceedingly meagre, and slightly bound together, scarcely 

 amounting to a mesh system, and the numerous small white 

 statospheres are found in recesses far larger than themselves. 

 This sponge has been called Meyenia cratcriforma. Another 

 forming beautiful green masses, often four to five inches in dia- 

 meter, and about a quarter of an inch in thickness, was found in 

 Cobb's Creek, near Philadelphia. The surface is irregular, occa- 

 sionally rising into rounded lobes ; the efferent canals are deeply 

 channeled in the upper surface of the sponge, five or six some- 

 times converging to a common orifice. The statospheres are 

 numerous — rather small. There are two series ol birotulate 

 spicules, and it has been called Heleromcyenia ryderii. The third 

 species was found at Lehigh^Gap, Pa., in November, 18S1, and 

 belongs to the genus Tubella. This genus, established by Carter, 

 contained only four species, all from the Amazon River. The 

 new species is small, encrus'ing, and has been called P. pennsyl- 

 vanica. The skeleton spicules are arranged in a simple series of 

 single non-fasciculated spicules, in the interspaces of which the 

 statospheres are abundant. These spicules are very variable in 

 size and shape, but all are entirely and coarsely spined. The 

 dermal spicules seem absent. 



Molluscous Fauna of Moscow. — The molluscous fauna of 

 the neighbourhood of Moscow was very little known rntil now, the 

 two former works dealing w ith this subject, by M. Ratchinsky 

 and M. Madcjine, giving only fifty-one species of Gasteropods, 

 that i«, only a half of this class of Mollu-cs which are to be 

 found in the neighbourhood of Moscow. M. Milachevitch fills 

 up this gap (Bull, de la Soe. des Naturalistes de Moscou, No. 2) 

 by giving a list of the Molluscs of this region, his determinations 

 of species having been made with the help of, or revised by M. 

 Clessin and Dr. Bottger. It is worthy of notice that of the 109 

 species described, II belong to the region of the Alps, and 17 

 to the boreal region, 7 of them being common to both regions, 

 and all the Alpine species having been widely spread in Germany 

 during the Quaternary period. A remarkable feature of the 

 Moscow molluscous fauna is the absence of the larger species of 

 Helix (// pomatia, H. nemoralis, H. arbuslorum, H. Iwrlensis, 

 &c. ), whilst they are frequent in other parts of the boreal region 

 — to which the Moscow molluscous fauna belongs too — nearer to 

 the sea. As to the southernlimits of the boreal region in Russia, 

 it is difficult to determine it, but M. Milachevitch supposes it to 

 follow a line drawn from Riga to Tamboff and Saratoff. 



Peristaltic Intestinal Movements. — The movements 

 of the intestine have been recently studied by the graphic 

 method, by Signori Mosso and Pelicani (Reale 1st. Lomb.), 

 experimenting both on man and the dog. Among other 

 results it appears that at every movement of respiration there 

 occur strong contractions of the rectum. Emotions and cerebral 

 activity have a very manifest influence on the mu cular fibres of 

 the intestine, cau-ing strong contraction. Besides so-called 

 spontaneous undulations in the tracings, the direct cause of 

 which is not known, it is possible, the authors prove, to contract 

 at will portions of the intestine that are a considerable distance 

 from the sphimeter muscle. The authors study the influence of 

 changes of temperature on the tonicity of the intestinal walls, 

 indicate the variations of the latter in sleep, digestion, and under 

 influence of medicaments, &c, and show how intestinal move- 

 ments are related to changes of volume in the forearm and 

 blood -pressure in the carotid. 



On the Occurrence of Root-florets in Catananche 

 lutea. — A paper on this subject by B. Daydon Jackson, 

 SecL.S., was read before the Linnean Society on May 4. — M. 

 J. A. Battandier, in writing to Sir John Lubbock, pointed out 

 the occurrence of certain large single florets produced directly 

 from the roots of this yellow-flowered composite. Examination 

 of the large series of specimens of this species contained in the 

 herbaria at Kew and the British Museum, showed that these 



