HareittT: Pennaria tiarella and Tubularia crocea, 
PLATE 2. 
Pennaria tiarella. 
All eggs killed in Bouin’s fluid, stained in iron hematoxylin and Congo red. 
Figs. 10a, 10b. Egg from same medusa as that of Figures 8a, 8b. First 
maturation spindle. Successive sections showing chromosomes, 
some in tetrads. X 2250. 
Fig. 11. Middle section of equatorial region of first maturation spindle. This 
egg had just been discharged from the medusa. Chromosomes 
splitting and showing x- and v-shaped figures. X 2250. 
Fig. 12. First maturation spindle. Asters entirely absent; the peripheral 
pole shows a centrosome. Chromosomes divided and separating. 
< 2250. 
Fig. 13. First polar cell detached; second polar cell forming. X 2250. 
Fig. 14. First polar cell detached. The chromosomes in the egg form a 
resting nucleus before the second maturation spindle appears. 
Radiations are the first indications of a new spindle. X 1600. . 
Fig. 15. Like Figure 14. The resting nucleus in several vesicles and both 
poles of forming second maturation spindle marked by asters. 
< 1600. 
Fias. 16a, 16b. The two germ nucleiof one egg. Fig. 16a, the sperm nucleus 
with an aster and large centrosphere; Fig. 16b, egg nucleus. 
x 1600. 
Fig 17a. Spermatozoén soon after entrance. Entrance cone on surface of 
the egg; a ‘‘track’’ behind the sperm head, and a large aster in 
front of it. 'Two other spermatozoa were present in the egg, but 
the cytoplasm was not differentiated about them. X 1600. 
Fic. 17b. Egg nucleus of same egg. > 1600. 
Fic. 18. Section of an egg showing a germinative vesicle (larger vesicle) 
and sperm nucleus (smaller vesicle). The only egg found where 
the spermatozoén was present before the polar cells had been 
formed. > 1600. 
