SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(PRINCIPALLY INVERTEBRATA AND CRYPTOGAMIA), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryology.! 



Effects of Alkalis and Acids on Developing Ova of Sea-Urchin.J 

 B. Moore, H. E. Eoaf, and E. Whitley point out that in nearly all cases 

 of malignant disease the secretion of hydrochloric acid by the gastric 

 glands is stopped or greatly reduced. This effect is not due to local 

 conditions in the stomach : it occurs wherever the growth is situated. It 

 is due to a change in the distribution of salts in the plasma whereby the 

 alkalinity is increased or the concentration in hydrogen ions diminished. 

 Addition of small amounts of alkalis or alkaline salts to the medium in 

 which sea-urchin eggs are developing, causes at first an increase in rate 

 of growth and division, but as the amount is increased, there is irregu- 

 larity in the size and shape of the cells produced — nuclear division gets 

 ahead of cytoplasmic division. With further increase, division stops. 

 Accompanying the increased stimulus to nuclear division, there are many 

 atypical forms of mitosis, as in malignant growths. The minutest 

 amount of added acid has an inhibitory effect upon growth and nuclear 

 division. The extreme limits at which life and cell-division are possible 

 lie close together, indicating that the cell is extremely sensitive to even 

 slight changes in the hydrogen and hydroxyl ion concentration. 



Effect of Acids and Alkalis on the Eggs of Plaice and Sea- 

 Urchin. § — E. Whitley has made experiments on the effect of acid, alkali, 

 and certain indicators in arresting or otherwise influencing the develop- 



* 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 pub- 

 lished, and to describe and illustrate Instruments, Apparatus, etc., which are 

 either new or have not been previously described in this country. 



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

 called, but also those dealing with Evolution, Development, Reproduction, and 

 allied subjects. 



% Proc. Roy. Soc, Series B, lxxvii., No. B 515 pp. 102-36 (30 figs.). 



§ Tom. cit., pp. 137-49. 



