ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 307 



with the virus of rabies, however, showed a distinct centrosome, which 

 apparently divides into two as the disease progresses. The two centro- 

 s )mes then migrate towards opposite poles. The author explains this 

 phenomenon in the following way : — The effect of rabies on the nuclei 

 of the nerve-cells is to produce regressive phenomena, — a process of 

 atrophy, which is preceded by a temporary tendency to proliferation. 

 This tendency is indicated only by the appearance of the centrosome, its 

 division, and the incipient migration of the new centrosomes. 



Central Corpuscles in Nerve-cells.* — Dr. Eud. Roister notes briefly 

 the finding of very distinct central corpuscles in the cells of the dorsal 

 nervous system in Gottus scorjpius. In some cases one central corpuscle 

 only was present, and in others two ; the two conditions occurring with 

 about equal frequency. In each case there was a central darkly-staining 

 granule surrounded by a clear area. Details are to be published later. 



Structure of Serous Gland-cells. f — Charles Gamier has investi- 

 gated the minute structure of the serous glands of Vertebrates, with the 

 object of studying the process of secretion, and the part played by the 

 ergastoplasm in the process. His paper includes an account not only 

 of his own observations, but of the observations and conclusions of 

 others, a historical sketch of the subject, and a very full bibliography. 

 The author gives an ideal sketch of the history of a gland-cell in the 

 following terms. The cytoplasm, at first nearly homogeneous, becomes 

 differentiated, and displays filaments having at first an acidophil re- 

 action ; at the same time the nucleus enlarges, undergoes various 

 changes, and eventually yields caryoplasmic substances to the ergasto- 

 plasmic filaments which become basophil. When this is accomplished, 

 the nucleus is reconstructed, and the basophil filaments give rise to 

 the secretion. As the secretory granules are differentiated, the ergasto- 

 plasrnic filaments disappear, the secretion is excreted, and the cytoplasm 

 is ready to begin the cycle anew. This series of changes cannot be ' 

 followed entirely in any particular case, for each gland has its special 

 peculiarities, but the author believes that it represents the most general 

 condition. The ergastoplasm is to be regarded as an intermediary 

 between the substances of plasmatic origin and the cytoplasmic proto- 

 plasm, and serves to transform for the cytoplasm the substances furnished 

 to it by the nucleus. According to other observers, it would appear that 

 in some cases the nucleus takes a more active part in secretion than is 

 indicated in this scheme. . 



Plastic Activity of Lymph-cells. — Prof. L. Eanvier describes under 

 this name a phenomenon which he has witnessed in the cells of rat- 

 serum. When the serum is warmed gradually up to 35° C. in a moist 

 chamber containing air-bubbles, the serum-cells approach the bubbles 

 and flatten themselves against them just as they do against a resistant 

 body. If the preparation is then cooled down to 21° C, the cells 

 recover their globular form, showing that the phenomenon is a vital 

 one. 



* Anat. Anzeig., xvii. (1900) pp. 172-3 (2 figs.). 



t Journ. Anat. Physiol., xxxvi. (1900) pp. 22-9S (3 pis.). 



X Comptes Rendus, cxxx. (1900) pp. 19-20. 



Y 2 



