574 SUMMARY OF CURRENT researches relating to 



SUMMA1IY 



OF CURRENT BESEABCHES RELATING TO 



Z OOLOGY AN D B T A N Y 



(principally Invertebrata and Cryptogamia), 



MICROSCOPY, &c, 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 



ZOOLOGY. 



A. VERTEBRATA :— Embryology, Histology, and General. 



a. Embryology-t 



Spermatogenesis in Mammals.! — Herr C. Benda, continuing Lis 

 account § of mammalian spermatogenesis (which is in essential agree- 

 ment with that lately given by Mr. H. H. Brown), j| discusses the 

 existence of an internal process from the "supporting cell." The 

 presence of a single process he regards as the artificial result of re- 

 agents, but affirms the existence of a brush-like bundle of fine filaments 

 with which the young sperms become connected. He describes the 

 elongation and subsequent retraction of the supporting cell, and shows 

 how in consequence of the latter, which is unusually marked in the 

 rat, the sperms come to be displaced even to the extent of reaching 

 the wall of the canal. 



The pointed pole of the young sperm represents the position first 

 connected with the supporting cell, and towards tbis pole the nucleus 

 moves, exhibiting a chromatin body which points in the same direc- 

 tion. The behaviour of this apical knob in uniting with the process 

 of the supporting cell, and the further modifications of the sperm-cells 

 are briefly described. 



Blastodermic Vesicle in Mammals. If — After giving a brief resume 

 of Van Beneden's account of the segmentation of the rabbit's ovum, 

 and referring to the theories of various writers as to the meaning and 



* The Society are not intended to be denoted by the editorial " we," and they 

 do not hold themselves responsible for the views of the authors of the papers 

 noted, nor for any claim to novelty or otherwise made by them. The object of 

 this part of the Journal is to present a summary of the papers as actually published, 

 and to describe and illustrate Instruments, Apparatus, &c, which are either new 

 or have not been previously described in this country. 



t This section includes not only papers relating to Embryology properly so 

 called, but also those dealing with processes of Evolution, Development, and 

 Reproduction, and with allied subjects. 



J Arch. f. Anat, u. Physiol. (Physiol. Abth.), 18S6, pp. 386-8. 



§ Cf. this Journal, ante, p. 209. 



|| Cf. this Journal, v. (1885) p. 783. 



i Scientif. Proc. R. Dublin Soc, iv. (1885) pp. 536-45 (7 figs.). 



