RECENT ADVANCES IN SCIENCE 43 



the result of a segregation of characters in the vegetative cells 

 of the plant. 



Physiology. — Osterhout (Bot. Gaz., June 191 7) has investi- 

 gated the effect of potassium cyanide on permeability and 

 finds that, in common with ether, chloroform, and alcohol, it 

 produces a temporary decrease in permeability. The author 

 suggests that this may be an outcome of its inhibiting effect 

 upon oxidation. 



ZOOLOGY. By Chas. H. O'Donoghue, D.Sc, F.Z.S., University College, 

 London. 



Protozoa. — A very great deal of work has been done, particu- 

 larly in America, on the multiplication and life-history of 

 Paramcecium, and the main results of this are generally known. 

 In spite of the great care taken in many of these experiments, 

 the supply of food has not been critically controlled, and this 

 beyond doubt plays a part in the matter of " depression periods." 

 Hargitt and Fray have investigated " The Growth of Para- 

 mcecium in Pure Cultures of Bacteria " (Jour. Exper. Zool. 

 vol. xxii. Feb. 191 7), and for the first time investigated by 

 modern bacteriological methods the effect of a strict food 

 control. The experiments had to be terminated, but in spite 

 of that a good deal of useful information has been accumulated 

 and the authors put forward several suggestions regarding 

 the precautions necessary in order to satisfactorily prepare the 

 cultures and compare more exactly than has been done before 

 the results obtained with those of the controls. 



Other papers include : " On the Reactions of Amoeba to 

 Isolated and Compound Proteins," by Schaeffer (ibid. Jan. 191 7), 

 " The Life-history of Amcebce of the Limax Type in the Human 

 Intestine," by Swellengrebel and Winoto (Parasit. vol. ix. 

 Feb. 191 7). 



Invertebrata. — G. H. Parker has conducted a series of experi- 

 ments on the biology of the anemone Metridium (Actinobola) 

 marginata which form a study of behaviour as tested by opera- 

 tions, etc. During the period under review the results are 

 recorded in a series of papers : " Nervous Transmission in the 

 Actinians," "The Movements of the Tentacles in Actinians," 

 " Pedal Locomotion in Actinians " (all in Jour. Exper. Zool. 

 vol. xxii. Jan. 191 7), and rounded off by a more or less 



