ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 657 



prolongations — which possibly have a lumen of lymphatic origin- 

 appear to stand in causal relation to the formation of deutoplasm, the 

 growth of the cell, and possibly also to the increase in size of the cell- 

 nucleus. In addition, there are fine fibrils, possibly of nervous origin, 

 also penetrating the cytoplasm. The present notice is preliminary, and 

 the author suggests various further lines of investigation, some of which 

 he hopes to pursue. 



I. Histology. 



Functions of the Nucleus.* — M. Henri Stassano lias been struck 

 with the resemblances between the changes of the nucleus in red blood- 

 corpuscles during the absorption of iron-salts, e.g. the saccharate, and the 

 phases exhibited in the development of these elements. He has been 

 led to the conclusion that the nucleus has to do with the assimilation of" 

 nutritive materials, with the elaboration of proteid substances like 

 haemoglobin, and with the protection of the cells against injurious 

 substances absorbed. 



Mitosis and Amitosis.f — Bombard Solger notes that his statement 

 that the nuclei of the myocardium in the pig probably multiply by direct 

 division has been contested by Hoyer on account of observations made 

 on the myocardium of the calf. Further observations in the case of the 

 pig have convinced Solger that his surmise was correct, and that the 

 nuclei do multiply there without auy sign of a karyokinetic process. 

 Even in the calf he has found indications of the occurrence of direct 

 division, as well as mitotic figures. Both processes therefore occur, but 

 the reasons for the ap])avently sporadic occurrence of amitotic division 

 have yet to be determined. The author briefly discusses the other cases 

 of amitotic division in plants and animals which have been described by 

 different authors, especially those cases where mitotic division is replaced 

 by the amitotic method. Though unable to explain the appearance of 

 the latter in the nuclei of the myocardium, he notes that according to 

 Godlewski the same thing occurs in the nuclei of striped muscles. 



Structure of Medullated Nerve-fibres.! — G. Sala summarises the 

 present condition of knowledge in regard to the so-called skeletal sub- 

 stance of the medullary sheath, which has been the object of many 

 investigations in recent years. He has been able to demonstrate not 

 only the spirally coiled fibrillse shown by Golgi to exist at the ends of 

 the medullary segments, but also a series of fine threads, often with 

 swollen nodes, which connect the successive spirals, and seem to serve 

 like them to support the substance of the medullary sheath. 



Nerve-endings in Sclera of Eye.§ — A . E. Smirnow notes that though 

 it has been shown that the tunica albuginea of the eye has a special 

 nerve-supply, nothing is known of nerve-endings in it. He has studied 

 the point in various mammals by the help of Golgi's method and the 

 methylen-blue method, and finds that, in addition to nerve-endings in 

 the walls of the vessels, sensory endings occur between the bundles of 

 fibres (true sensory endings), and also upon the connective-tissuc- 

 corpuscles (probably trophic end-organs). 



* Comptes Rendus, cxxxi. (1900) pp. 298-301. Cf. this Journal, ante, p. 5G& 



t Anat. Anzeisr., xviii. (1900) pp. 115-21 (4 figs.). 



J Tom. cit.. pp. 49-55 (1 pi.). § Tom. cit., pp. 76-80 (3 figs.). 



