934 SUMMARY OF CURRENT RESEARCHES RELATING TO 



SUMMARY 



OF CURRENT RESEARCHES RELATING TO 



ZOOLOGY AND BOTANY 



(principally Invertebrata and Cryptogamia), 



MICROSCOPY, &c, 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS* 



ZOOLOGY. 



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



a. Embryology, f 



Idioplasm and Nuclear Substance. :j: — To the numerous recent 

 contributions to the theory of heredity, a critical review is added by 

 Dr. J. Frenzel. 



In the first portion of this survey he discusses the nature of sexual 

 reproduction, noting the different opinions as to the role of the nuclei, 

 the import of the sperm protoplasm, polyspermy, &c, concluding that 

 the real male substance is probably confined to the nucleus, though 

 the denial of any important function to the associated protoplasm is 

 not, as yet at any rate, justified. 



The second chapter is devoted to a treatment of asexual repro- 

 duction, with a discussion as to the definitions of cell and nucleus, 

 the striking absence of demonstrable nuclei in numerous instances, the 

 existence of diffused " pseudochromatic " substance, and the probable 

 morphological solution of the nucleus in various cells. 



Lastly, he reviews the opinions held in regard to the real inherited 

 substance, framing a number of evident generalizations, and as a 

 general conclusion suggesting that the specific characters are trans- 

 mitted by the nuclei, while the reappearance of the general characters 

 of the species is ensured through the protoplasm of the egg-cell. A 

 lucid review of many important researches is available in this lengthy 

 paper, which does not, however, contribute any important new sug- 

 gestion to the solution of the problem of heredity. 



* 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. 



t Arch. f. Mikr. Anat, xxvii. (1886) pp. 73-128. 



