1902.J NATURAL SCIENCES OF PHILADELPHIA. 15 



A deep constriction in the deutomerite will cause such a flow. The 

 phenomenon just mentioned, however, is to all appearances of a 

 totally different nature. It shows itself as a shifting, eii masse, of 

 all the granules in sight. There is no flowing, and, so far as it is 

 possible to see, the granules maintain somewhat the same relative 

 positions. 



The reasons for supposing the muscular layer is involved in this 

 phenomenon are as follows : The muscular layer lies upon and is 

 directly continuous with the endoplasm. The latter is beset with 

 granules to its extreme limit. Away from the surface, there is 

 nothing to prevent a flow of these granules, but on the surface (of 

 the endoplasm) it is not unreasonable to suppose that the netlike 

 muscular layer entangles a number of these granules. In conse- 

 quence, when the muscular layer contracts, the superficial granules 

 are carried along with it. That there are granules embedded in 

 the muscular layer is indicated by what is seen in plasmolyzed 

 gregarines. In such animals, when the muscular layer is torn loose 

 from the endoplasm, it always carries with it a number of granules. 



The transverse movement is indifferently to one side or the other, 

 or else to and fro. It is displayed conspicuously when the grega- 

 rine is beha\nng in the manner described on pp. 12 and 13, and 

 illustrated in fig. 12. It also takes place when the animals turn, 

 and frequently in such cases the cuticular markings and superficial 

 granules are seen to sweep rapidly to one side, suggesting that the 

 gregarine is rotating on its long axis. That such a rotation actually 

 takes place can be confirmed by watching gregarines which have 

 the nucleus out of the middle line, or some other mark which ren- 

 ders it possible to distinguish one side from the other. 



In other cases there is nothing to demonstrate a rotation. The 

 transverse movement is slight and slow, being first to one side and 

 then to the other. This is seen when the animal is displaying the 

 slow typical glide. Should the animal then turn, the transverse 

 movement becomes more extensive and more rapid, while if pro- 

 gression be in any ways interfered with, a still greater increase in 

 the speed and extent of the transverse movement takes place. 



Ail of this occurs without the extensive muscular contractions 

 which gregarines so frequently display. But it is possible to estab- 

 lish a correlation between the transverse movement and what is 

 clearly a dis])lay of muscular activity. When a gregarine displays 



