140 



COMPARATIVE ANATOMY 



eventually ceased; at the same time the large albuminous 

 granules seemed to dissolve and the whole cytoplasm became 

 minutely granular, all distinction between ectoplasm and 

 endoplasm being lost. After a period of rest the streaming 



dt 



2). 



A , a single reproductive cyst of Amoeba j>roteus> magnified about 60. .fl, a 

 section through a group of seven cysts of A. proteus, x 60. C, a section 

 through a single cyst, X about 180. ./?, a section through a cyst with 

 some 600 nuclei showing the differentiation of the pseudopodiospores 

 at the periphery of the cyst ; the cyst-wall is not represented JX about 

 200. E, a single free pseud opod iospore ;x about 175. f\ dividing 

 nuclei of a cyst, showing dumbbell-shaped and horseshoe-shaped 

 forms 5x625. G, one of the peripheral nuclei from D;X75o: the 

 nuclear membrane is distinct, and the chromatin collected in the 

 centre of the nucleus, a, 3, c, outer, middle and inner layers of the 

 cyst-wall, dt, granules of reserve material or deutoplasm. gl, gelatin- 

 ous investment holding the cysts together, n, nuclei, ps, pseudo- 

 podiospores. (After Scheel.) 



movements began again, and the Amoeba rotated slowly and 

 continuously about its centre, first in one direction, then in 

 another, but without changing its position. As it rotated it 

 formed a thin coat or cyst-wall, as a secretion from its outer 

 surface, and the nucleus divided several times by amitotic 

 divisions. A single specimen was observed to rotate in this 

 manner for four days, at the end of which time about twenty 



