62 SUMMARY OF CURRE.^T RESEARCHES RELATING TO 



I)efore germination to expel drops of vitelline material. This prevents 

 over-svvelling of the cells, and it may also lead to cell-division by re- 

 ducing the vitelline maws, for cell-division is slowed by the presence 

 of much vitelline substance. J. A. T. 



Protozoa. 



Heredity and Variation in Arcella dentata. — R. W. Hegner 

 {^Genetics, 1919, 4, 95-150, 26 figs.). The main problem attacked is, 

 Can heritably diverse lines be recognized among the descendants of a 

 single specimen of Arcella dentata multiplying vegetatively ? It was 

 found that a large family 'so derived consists of a number of branches 

 that are hereditarily diverse with respect to diameter and number of 

 spines. These diverse branches resemble the hereditarily diverse families 

 that were obtained by vegetative reproduction from different " wild " 

 specimens. The formation of such hereditarily diverse branches appears 

 to be a true case of evolution that has been observed in the laboratory, 

 and that occurs in a similar way in nature. J. A. T. 



Culture of Amoebae. — Monica Taylor {Proc. R. Physical Soc. 

 EcUnhurgh, 1919, 20, 179-82). Amoebae were found flourishing in the 

 more or less undisturbed mud with abundant organic debris in flowing 

 water which secures good aeration. By adding wheat grains to the 

 mud and by having sufficient water-weed to secure aeration, successful 

 cultures were kept up in the laboratory throughout the winter. Plentiful 

 food and good oxygenation seem to be the most important conditions. 



J . A. J.. 



Malarial Parasite in Blood of Buffalo. — A. L. Shearer (Bull. 

 Agric. Research hist. Pusa, 1919, 90, 1-5, 2 pis.). The blood of an 

 Indian buffalo showed small and large ani dividing forms of what is 

 probably a new species of Plasmodium, for which the name hulalis is 

 proposed. J. A. T. 



Toxicity of Acids to Ciliate Infusorians. — M. E. Collett {Journ. 

 Exper. ZooL, 1919, 29, 443-72, 6 graphs). The order of toxicity of a 

 series of acids varies with the concentration, the temperature, and the 

 species. The action is therefore not simple. The H-ion is an im- 

 portant factor, but not the only one. The anions of formic, acetic, 

 propionic, butyric, valeric, citric, benzoic, phthalic, and salicylic acids are 

 toxic to both Paramecium and Euplotes. The anions of oxalic, tartaric, 

 lactic, and malonic acids are toxic to Paramecium, but not to Euplotes. 

 The temperature co-efficients indicate that both chemical and physical 

 reactions are probably concerned in the toxic effect of acids. A most 

 marked irregularity is shown by acetic and butyric acids, in that their 

 toxicity to Euplotes (though not to Paramecium) is greatly increased by 

 temperatures below as well as above 20° C. J. A. T. 



Ciliata of Lahore.— B. L. Bhatia {Records Indian Musewn, 191 G, 

 12, 177-83, 3 figs.). Notes on Paramecium caudat^im, with three con- 



