37G W. H. TALIAFERRO 



try to show that such is the case in the reactions of Allolobo- 

 phora sp. to light. They find that there is a tendency for this 

 animal to swing the anterior end in regular alternation from side 

 to side in successive extensions and a tendency in orientation 

 to light for the animal to swing directly away from the source 

 of stimulation. As one would expect from the action of these 

 two tendencies they find that the anterior end of the worm is 

 swung away from the light most frequently when it is directed 

 toward the light and least frequently when it is directed away 

 from the light at the moment the light is turned on. 



In a paper on the physiology and histology of the statocysts 

 of Pecten, Buddenbrock (4) finds that this animal in directing 

 its course makes use of two different methods. There is (1) 

 vertical steering (Vertikalsteuerung) in which the animal can 

 direct itself in any direction in relation to gravity by turning 

 about its transverse axis, viz., the axis which passes in general 

 between the right and left valves in an anterio-posterior posi- 

 tion. In this mode of steering the animal uses the so-called 

 " position reflex " and the reflex from the left statocyst. Then 

 there is (2) side steering (Seitensteuerung) in which the animal 

 can direct itself in any direction in a horizontal plane by turning 

 about its vertical axis, viz., the axis passing through the center 

 of the animal perpendicular to both valves. In this method the 

 animal uses the reflex from the left statocyst alone. In no case 

 is a reflex from the right statocyst used. This lack of function 

 corresponds to its degenerate histology. The same author (5) 

 gives a very extensive criticism of Loeb's tropism theory. Space 

 will not permit a consideration of his various arguments against 

 this theory. 



In a paper which deals chiefly with the cytology of the different 

 stages of the encystment of Amoeba proteus, Carter (6) gives 

 some details of the behavior during the process of encystment. 

 The animal becomes sluggish and exudes a slimy mucous sub- 

 stance, which causes diatoms, debris, etc., as well as cast off 

 waste products to adhere to the animal and thus form a pro- 

 tective wall. The Amoeba as well as the mass of debris then 

 assumes a spherical form. 



Cary (7) (8) finds that although regeneration can take place 

 normally in Cassiopea xamachana without the influence of the 

 marginal sense organs, the rate of this regeneration is decidedly 



