DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
593 
the first cleavage some influence is exerted on the color markings within the egg 
(previously described as clustered rather closely around the opaque center), which 
suddenly, as through an explosion, become rather widely scattered within the egg 
(fig. 93). 
The second cleavage plane generally follows the first very quickly. In fact some 
eggs reach the four-cell stage as quickly as the two-cell stage is attained in others. 
An irregularity in size and shape of the cells remains evident. It is obvious, also, 
that the purple and orange markings have increased somewhat in size (fig. 94). 
The eight-cell stage may be expected about 2 / to 3 hours after fertilization, when 
the water temperature ranges from 27° to 28° C. The cells, although not plainly evi- 
dent throughout, appear even more irregular and unequal in size than in the earlier 
stages. The purple and orange spots, or spheres, have continued to increase in size, 
Figure Q3.—Hypleurochilus geminatus. From egg in 2-cell 
stage; 154 hours after fertilization. 
Figure 94 . — Hypleurochilus geminatus. From egg in 4-cell 
stage; 154 hours after fertilization. 
some of them being nearly twice as large as in the four-cell stage, and they cover most 
of the germinal disc, further obscuring vision of the segmental processes (fig. 95). 
The eggs that failed to adhere to the slides by means of the foot, because of crowd- 
ing or other causes, did not develop. It is important, therefore, that they become 
attached in the proper position. Judging from the neat and even arrangement of 
the eggs in the “nests”, it would seem highly improbable that a loss from a similar 
source would occur in nature. 
The 16-cell stage follows the 8-cell stage rather quickly and may be expected 
within about 2 / to 3 % hours after fertilization at a water temperature of 27° to 28° C. 
The cells remain irregular in shape and unequal in size. The germinal disc now 
spreads over nearly the entire upper surface of the yolk (fig. 96). 
Cell division continues to progress rapidly, the 32-cell stage following the 16-cell 
one very quickly. Owing to the opaqueness of the egg and the large color mar kin gs, 
segmentation is very obscure and it generally cannot be followed after the 32-cell 
stage is reached. The germinal disc now appears to cover the entire upper surface 
of the yolk. The large opaque center of the egg remains unchanged. In the advanced 
cell stages the purple spots, varying among themselves in intensity, have all become 
somewhat less brilliant in color and are irregularly distributed in the yolk. The 
