YELLOW-BROWN CELLS OF CONVOLUTA PARADOXA. 479 
white by reflected light. In the mature female the amount of excretory sub- 
stance is considerably less than in the male and immature stages. 
Fres. 11, 12, 18.—Yellow-brown cells (x 330) as seen in just infected 
animals. In Fig. 11 the infecting cell has many chloroplasts differentiated 
into elongated, ‘ boat-shaped,” and polygonal. In Fig. 18 only three chloro- 
plasts occur, but the differentiation into the two forms is already indicated. 
Fie. 14.—Young C. paradoxa (x 45) 1—2 days after hatching; con- 
taining one large infecting cell and numerous colourless vacuoles. 
Fig. 15.—a. The infecting cell of Fig. 14 enlarged (L. 2, 54,), showing 
peripheral, elongated, brown chloroplasts, and more central group of yellow, 
polygonal bodies, more suggestive of spores than of chloroplasts. 4d. The 
same cell undergoing changes of shape, due to the movements of the animal. 
e. The contents of (4) liberated in the body of the animal. 
Fic. 16.—Ezge capsules of C. paradoxa showing yellow-brown cells, one 
with pointed clear anterior end attached to the egg membrane. 
Fie. 17.—Yellow-brown cells identical with those of the infecting alga 
occurring in the remnants of the ege capsule of C. paradoxa, 
Fie. 18.—a, 4, c, d. Yellow-brown cells showing nucleus. e. Minute 
yellow-brown cells showing stages of development from e, with single chloro- 
plast to e, with several and e, with numerous chloroplasts (L. 8, #5). 
VoL. 52, PART 4,—NEW SERIES. 37 
