Sept. 20, 1877] 



NA TURE 



435 



machinery may safely be left to the Institutions of Civil 

 and Mechanical Engineers, as well as the consideration 

 of the applications of iron and steel. The subject of 

 corrosion is one, however, which, though rather apper- 

 taining to the finished product than to its manufacture, 

 is one which should not be altogether overlooked, for if, 

 by any variation in the process of production, the effects 

 of corrosion may be diminished or modified, a new value 

 will be given to the finished product. 



There is one thing, however, which, as we hinted at 

 the beginning of this article, has no place in the delibera- 

 tions of a body holding a scientific position such as the 

 Iron and Steel Institute, and that is the consideration of 

 commercial questions as such and apart from the influence 

 of science upon the cheapening of the cost of production 

 or the lessening of labour. There must be, no doubt, in 

 a society composed to so great an extent of men largely 

 interested in the commercial aspect of the manufacture of 

 iron and steel, a great temptation and tendency for the 

 discussions occasionally to diverge into commercial ques- 

 tions ; but it will be the duty of the president for the time 

 being to check such digressions and to keep the discussions 

 within legitimate channels ; and it will be one of the 

 objects of the council to allow no paper to come on for 

 reading or discussion which is not calculated to advance 

 the technical and scientific interests of the Institution over 

 which it has been called to preside. 



With the present cruncil, and under the presidency of 

 so distinguished a worker in science as Dr. Siemens, there 

 is evei-y prospect of the Iron and Steel Institute keeping 

 up its high scientific character, and we cordially wish it 

 every possible success. C. W. C. 



COHN'S BIOLOGY OF PLANTS 

 Beitriige zur Biologic dcr Pflanzeii. Herausgegeben 

 von Dr. Ferdinand Cohn. Zweiter Band. Erstes Heft. 

 (Breslau, 1S76: J. N. Kern.) 



THE first part of the second volume of Cohn's 

 Beitriige contains five papers, two of them being 

 illustrated with three plates each. The first paper is by 

 Dr. Leopold Auerbach, " Cell and Nucleus," remarks on 

 Strasburger's work,"Ueber Zellbildung und Zelltheilung." 

 It is a critical paper, and hardly admits of any condensa- 

 tion. He tries to controvert the statements of Stras- 

 burger, and sums up thus : — I. The longitudinally 

 striated body in the interior of the cell is not the 

 " nucleus," but the middle part of the so-called "karyo- 

 litic figure," and therefore a product of the mixing of the 

 special substance of the nucleus with the surrounding 

 protoplasm ; and 2, That the young nuclei do not develop 

 by the fission of the mother nucleus. 



The second paper is one of great importance, dealing 

 as it does with one of the carnivorous plants. It is by Dr. 

 A. Fraustadt. "Anatomy of the Vegetative Organs of 

 Dionasa muscipula, Ellis," with three plates. As Dr. 

 Fraustadt gives a very useful summary of results, we may 

 here quote them. Each half of the lamina is slightly 

 bent in a sigmoid manner, and forms a cavity to retain 

 an insect, while the petiole is broadly winged and flat- 

 tened. The cells of the epidermis, as well as those of the 

 ground tissue, are elongated in the direction of the long 

 axis of the leaf, in the petiole and midrib of the lamina, 

 but in the transverse direction in the rest of the lamina. 



The cells forming the epidermis contain chlorophyll 

 grains. The epidermis forms numerous stomata and 

 stellate hairs on the upper and lower surface of the petiole, 

 and under-surface of the lamina, but glandular hairs only 

 on the upper surface of the lamina. The glands are placed 

 in depressions in the epidermis, and are formed of a two- 

 celled basal portion, a two-celled short stalk, and a round 

 secreting part of two layers of cells convex on the upper 

 side. The stellate cells are similarly constructed, except 

 that the cells of the top layer grow out in radiating 

 straight arms, giving the whole a star-like appearance. 

 The stellate hairs appear early and are completely 

 developed before the glands begin to form. The stel- 

 late hairs and glands are homologous structures. The 

 lamina bears on its margin numerous (from fifteen to 

 twenty) teeth or marginal sets, and usually six spiny 

 hairs .(central seta;) on the upper surface. The marginal 

 setae are slender, triangular, pyramidal, and have stellate 

 hairs and stomata on all sides. A fibro-vascular bundle is 

 present running nearer the upper than the under side of 

 the structure. Between each of the marginal seta a single 

 stellate hair is placed sometimes elevated on the top of a 

 small projection, which, however, receives no fibro- 

 vascular bundle. The central setae consist of two parts, 

 the lower forming a joint, and receiving an axile cellular 

 string ; the upper part is conical, contracted below, and 

 has no cellular string. The cells of the central seta 

 show aggregation of the protoplasm (as described by 

 Darwin in Drosera), as well as those of the glands. In 

 the green parts of the petiole (above ground), and in the 

 midrib of the lamina, the cells of the ground- tissue increase 

 in length and in size of cavity from without inwards, the 

 superficial cells, and those near the fibro-vascular bundles 

 are green, the others colourless. In the lamina, with the 

 exception of the midrib, the inner cells of the ground 

 tissue are colourless, very broad, with sinuous walls and 

 small intercellular spaces. The epidermal cells of the 

 upper side of the lamina and the ground- tissue cells below 

 it, are larger than those of the under side. The chloro- 

 phyll grains contain abundance of starch before the leaf 

 has obtained any organic (animal) nourishment. The 

 starch diminished after the reception of organic (animal) 

 matter by the leaves, and lastly disappears entirely from 

 the parts of the plant above ground. The bases of the 

 petioles are dilated into colourless sheath-like portions 

 developed underground and together forming a kmd of 

 bulb. The ground tissue consists entirely of equally broad 

 and long cells completely filled with starch, as well before 

 as after the reception and absorption of organic (animal) 

 matter. The starch grains in the part above ground of 

 the petiole and lamina are oval ; in the basal sheathing 

 part of the petiole, on the other hand, the grains are cylin- 

 drical or rod-like. 



The living cells of the lamina and petiole contain a 

 colourless substance dissolved in the cell-sap, precipitated 

 by bases in the form of dark grains which are redissolved 

 by acids. The glands contain no starch. The red colour- 

 ing matter of the glands becomes converted into green by 

 the action of strong bases as ammonia and potash, but 

 is again restored by the action of acids. The colour 

 seems, therefore, to be identical with the red colouring 

 matter of plants so fully described by Prof. A. H. Church 

 in a recent number of the Jottrnal of the Chemical 



