and Laboratory Methods. 1767 



GENERAL PHYSIOLOGY. 



RAYMOND PEARL, University of Michigan. 



Books and Papers for Review should be Sent to Raymond Pearl, Zoological Laboratory, 

 University of Michigan, Ann Arbor, Mich. 



...^ , . ,. ^-r . ^, ■ , , The purpose of the author in this work 



Mlisukuri, K. Negative Phototaxis and other ^ ^ 



Properties of Littorina as Factors in de- was to determine the physiological 



termining its Habitat. Annot. Zool. factors which bring about the charac- 

 Japon. 4: 1-19, 1901. °. 



teristic distribution in Littorina exigiia 



on the rocks at about the level of high tide mark. The first and most important 

 of these factors is the marked reaction to light which the author designates as 

 " negative phototaxis." From the account of the experiments given it would 

 appear that the reaction is probably negative photopathy rather than phototaxis. 

 The animals go to the region of less light intensity. This reaction would tend 

 to cause them to move towards the land " which appeared naturally darker on 

 account of bushes, grasses, etc." The organisms are also found to have a ten- 

 dency to avoid submergence, this negative hydrotaxis working with the negative 

 " phototaxis " to cause them to move up towards land. When experiments were 

 so arranged as to force the animals by the light to go towards the water it was 

 found that they would not plunge in directly, but instead would crawl horizontally 

 along the edge. The reaction to light will eventually overcome the hydrotactic 

 reaction. The reason for the animals being in nature uniformly distributed over 

 the rocks is found in the habit they display of coming to rest in crevices 

 (thigmotaxis). On glass plates they will continue moving until an obstacle 

 is encountered. When the animal is splashed by water for some time 

 its " phototactic " reaction in many cases becomes changed from negative to 

 positive. This positive reaction is not as pronounced and permanent as the 

 negative. As a result of this reaction the animals tend to move down towards 

 the sea as the water recedes after high tide. This correlates with the fact that 

 Littorina is unable to move on a perfectly dry surface, requiring a certain amount 

 of moisture for movement and feeding. The author explains the origin of the 

 factors in the behavior as the result of natural selection. R. p. 



Jacobson. R. Uber die Wirkung fluoresciren- This paper is a direct continuation of 

 der Stoffe auf Flimmerepithel. Zeitschr. f. the work of Raab (Zeitschr. f. Biol. 

 Biol. 41: 444-466, .901. g^ gg^ ^^ ^^^ ^^^j^^ ^f fluorescent 



substances on infusoria. The results of this investigator are now extended to 

 ciliated epithelium. The material used was the ciliated epithelium from the 

 mouth of the frog and the fluorescent substances tested were : (a) eosin, in con- 

 centrations of from 1 : 100 to 1 : 2000 ; (b) harmalin (CigH^^NgO) in concen- 

 trations of from 1 : 1000 to 1 : 100000 (?) ; (c) akridin, in concentrations of from 

 1 : 5000 to 1 : 20000; (d) " Chinolinrot " (CaeHigNgCl) in solutions ofl : 5000 

 and 1 : 10000. In the experiments similar pieces of living epithelium on which 

 the cilia were actively beating were placed in dishes containing the solutions to 



