728 SUMMARY OF CUREENT RESEARCHES RELATING TO 



SUMMARY 



OF CUREENT EESEABCHES RELATING TO 



ZOOLOaY AND BOTANY 



(principally Invertehrata and Cryptogamia), 



MICROSCOPY, &c., 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 



ZOOLOGY. 



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



a. Embryology, t 



Theory of Sex and Reproduction.l — In a paper entitled "Theory of 

 Growth, Eeproduction, Sex, and Heredity," Mr. P. Geddes seeks to interpret 

 these in terms of their " fundamental secret, that of constructive and destruc- 

 tive metabolism — anabolism and katabolism." 



(1) Following Spencer, grotvth is more intimately defined as the pre- 

 ponderance of an anabolic tendency, rhythm or diathesis, while the limit of 

 growth corresponds to the maximum of katabolic preponderance consistent 

 with life, in other words to the climax of the katabolic diathesis. 



(2) Beproduction in all its forms is similarly treated. Like continuous 

 cell-division, asexual reproduction occurs when waste or katabolic processes 

 are in the ascendant. The phylogenetic evolution of sexual dimorphism, 

 which is briefly summarized, is interpretable as the gradual differentiation 

 of comparatively sluggish, more nutritive, preponderatingly anabolic (female) 

 cells, and more mobile, finally more exhausted, and emphatically katabolic 

 (male) elements. The evolution of fertilization by gradual stages from the 

 almost mechanical flowing together of exhausted cells (or plasmodia) is 

 sketched. By reference to aphides, plants, &c,, the author illustrates how, 

 just as asexual reproduction occurs at the limit of growth, a check to the 

 asexual process involves the appearance of the sexual, which is thus 

 only associated with katabolic preponderance. In many fungi it may be 

 seen that the greater the anabolism the less sexuality. Some beautiful and 

 suggestive illustrations are given of the relation of sexual to asexual repro- 

 duction. Alternation of generations is interpreted as a rhythm between a 

 relatively anabolic and katabolic preponderance, and other phenomena of 

 reproduction are similarly rationalized. 



(3) Nature of Sex. — Proceeding first on inductive lines, the author shows 

 (a) that the male and female elements exhibit in fundamental and concen- 

 trated expression the katabolic and anabolic antithesis ; (b) that the same 



* 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 Evolution, Development, and Reproduction, and allied 



i Proc. R. Soc. Edin., 1886, pp. 911-31. 



