682 GEOFFREY LAPAGE 



set of four might appoar all in differont positions from the first 

 set, so that the sphere appeared to contain more than four 

 contractile vacuoles. 



The appearance of odd numhers of contractile vacuoles in 

 this way, their occasional coalescence, their irregular pulsation 

 rate, their multiple numher, often subsequently reduced, 

 together with the presence of several contractile vacuoles in the 

 amoebae in the same preparations, suggested that abnormal 

 phenomena were being witnessed. The physical conditions of 

 the hanging drops were probably responsible for some of these 

 irregularities. But the absence of contractile vacuoles from the 

 spheres while they were still in the amoebae, and their appear- 

 ance in them after they were set free, proved, at any rate, that 

 the spheres were not mere dead defaecated matter, but were 

 ahve and were attempting to adapt themselves to the sudden 

 change in their environment. 



This view was confirmed by the occurrence in some, though 

 not by any means in all, of the spheres, of tentative amoeboid 

 movements, which, in a few cases, resulted in the sphere being 

 transformed into an active small amoeba. 



5. Amoeboid Movements in the Free Sphere. 



In several cases spheres which were extruded under observa- 

 tion were kept under observation for several days, in the hope 

 of some change being observed in them. In most of these 

 cases the only change was the appearance of contractile 

 vacuoles, the pulsation rate of which gradually became slower 

 and slower, until they stopped and the spheres disintegrated. 



In other cases, however, the spheres not only acquired con- 

 tractile vacuoles, but also exhibited slight amoeboid movements. 

 These were often no more than slight changes of form, but 

 definite small pseudopodia were sometimes put out (Text-fig. b). 

 In other rare cases the sphere became transformed into a small 

 active amoeba, which moved out of the field of observation. 



Text-fig, B represents drawings made "v\dth the camera lucida 

 of the changes undergone by such a sphere, and in Text-fig. a 

 are freehand drawings of another case. It is interesting to 

 note that, although in the period between extrusion and the 



