SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 

 a. Embryology. t 



Determination of Sex.| — Oskar Schultze communicates a full 

 account of his experiments on mice designed to test whether alteration 

 in nutrition had any effect on the proportions of the sexes in the off- 

 spring. His results are decidedly in favour of an answer in the negative. 

 He gives a masterly review of the whole subject, and concludes that 

 sex is determined in the early stages of oogenesis. 



General Embryology.§ — E. Korschelt and K. Heider give in the 

 first instalment of the " general " part of their treatise on the compara- 

 tive embryology of invertebrates an account of the structure, matura- 

 tion, and fertilisation of the germ-cells, and a review of all the recent 

 work on the physiology of development. 



Mechanics of Development. ||— S. J. Hickson gives a lucid account 

 of recent work in experimental embryology. " The facts which to-day 

 may convince us that there is no preformation of structures in the 

 animal egg, that there is no ' mosaic ' arrangement of the particles of 

 primordial protoplasm, may, in the course of time, be supplanted by 

 others, which will lead us to a reconsideration of our opinion. We 

 have at least learned to realise that no simple, physical or mechanical 

 explanation will ever solve the problem of the living substance of the 

 egg-cell. We may learn the effect of gravity, of temperature, of various 

 kinds of intensities of light, or of chemical and electrical stimuli, upon 

 protoplasm ; but we have not yet got within measurable distance of an 



* 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, etc., 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 Evolution, Development, Reproduction, and allied subjects. 



t Arch. Mikr. Anat., lxiii. (1903) pp. 197-257. 



§ Lehrbuch. d. vergleich. Entwicklungsges. d. wirbellosen Thiere. Allg. Theil. 

 Erstc Lief. 8vo, Jena, x. and 750 pp.. 



|| Rep. and Trans. Manchester Micr. Soo, 1902 (published 1903), pp. 28-37. 



