300 ERNEST WAREEN. 



Fig. VJ. — x 1440. A flame-cell with the convoluted capillary duct. The 

 cytoplasm of the flame-cell is not separable from the general protoplasmic 

 reticulum of the body {p.). The composite origin of the flagellum is 

 indicated by the distinct longitudinal striation, and the intermediate piece 

 between the nucleus and the flagellum is well seen {d. p.). A possible 

 aperture occurs on one side (cp.). 



Fig. VII.— X 40. An encysted animal, viewed as a transparent object. 

 The ventral surface is outermost. Eggs and excretory cells can be seen in 

 the space between the body of the animal and the cyst-wall. 



Fig. VIII (1). — X IGO. Section through the edge of a cyst. The space within 

 is the cavity of the cyst between the small portion of body [d.), cut through, 

 and tiie cyst-wall. In the space are siiown excretory cells in the process of 

 disintegrating into the nodulated material (/. mL), which becomes plastered 

 against the inside of the cyst-wall, and increases its thickness. 



(2). — X 320. A piece of the cyst-wall under greater magnification. In 

 the upper portion an excretory cell is being flattened against the inner surface 

 of the cyst, while below the more usual disintegrated substance can be seen. 



Fig. IX. — X 225. The upper portion of the excretory bladder, with the 

 right and left main ducts opening into the lining epithelium on each side. 



Fig. X — X 200. Excretory epithelia from the bladders of five indi- 

 viduals. 



(1) Shows the apparent fibrils (/.) and a few osmieated globules of fat. 



(2 and 3) The cells possess many vacuoles which are collecting into 

 larger vacuoles. 



(4) The cells generally possess one large vacuole with granular contents. 



In the lower part of the figure can be seen a cell in the act of 

 budding. 



(5) The large vacuoles have become emptied. 



Fig. XI. — X 250. Various stages in tiie development of the sexual form. 



(1) Egg in side view showing egg-cell {e(/. c.) and yolk-cells. 



(2) Segmentation has occurred, producing a number of large blastomeres 



with badly staining nuclei. 



(3) Tiie sporocyst embedded in the superficial substance of the testis of 



the crayfish ; the general arrangement of the blastomeres appears 

 . quite irregular. The yolk-cells are becoming flattened («. y.). 



(4) A budding sporocyst in surface view. 



(5) A budding sporocyst in surface view. 



