228 MISCELLANEOUS EXAMPLES 



Comparison of Fig. 44, A and B will make this plain, even when 

 due allowance has been made for their different degrees of enlarge- 

 ment. The same greater size of the specimens of Actinophrys, 

 with which another cell of A'', o^aca was densely packed, is shown 

 in Fig. 45, A (x 125). The organisms here were all completely 

 decolourised, and, through the centre of the cell, a large dense 

 aggregation of Bacteria was to be seen, in the midst of which 

 many of the Actinophrys were embedded. 



I have tried on several occasions to get photographs of these 

 specimens of Actinophrys, but with no success. All reagents have 

 proved useless because they, at once, entail a retraction of the 

 pseudopodia. And, however motionless the Actinophrys appears 

 to be, the photograph generally shows that it is only relative. 

 The best I have been able to do is shown in my " Studies in 

 Heterogenesis " in Fig. 177, A ( X 375), which was taken with a 

 very i-apid plate and an exposure of one minute. The nucleus 

 and nucleolus are to be dimly seen, together with six or more rays ; 

 and this represents the common appearance of the organism in its 

 active state. After from about seven to ten days, when their 

 scanty food is more or less exhausted, this active state is over, 

 and the organisms then encyst themselves, when they present the 

 appearance shown in Fig. 45, B ( X 375). 



Once in the encysted condition, specimens of Actinophrys seem 

 to remain long without undergoing any further change. I kept 

 some of the above described specimens in a small tube for about 

 six weeks, but at the expiration of that time they showed no 

 appreciable alteration, except that the enclosed protoplasm 

 seemed a little less granular than it had been previously. 



I have already alluded to the fact that the Monad, the Amoeba, 

 and the Actinophrys are only different phases easily convertible 

 the one into the other. This is thoroughly recognised as regards 

 the Monad and the Amoeba, and fresh evidence thereof is con- 

 stantly to be met with in studying the results of segmentation of 

 the common Amoeboid spheres in Nitella — sometimes the products 

 appear as Monads and sometimes as Amoebas, without any reason 

 for this variation being apparent ; and a similar interchangeability 

 between these two forms was met with in the colourless segmenta- 

 tion products of Zoogloea, as already described in Chapter X. 

 During my examination of the specimens of Actinophrys crowding 

 the cells in N. opaca, wishing to preserve one of the cells mounted 



