DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
607 
The blastodisc is large and projects prominently beyond the yolk. The pervi- 
telline space is wide at the positive pole of the egg and very narrow or wanting at the 
negative pole (fig. 111). The first blastomeres are large and about equal in size, as 
usual in teleosts (fig. 112). The second cleavage plane is approximately at right angles 
to the first, and it followed the first, at a water temperature of about 26° C., in about 
20 minutes (fig. 113). The third and fourth cleavages followed equally as rapidly. 
Figure 113. — Chasmodes bosquianus. From egg in 4-cell stage; 
about 2H hours after fertilization. Owing to opaqueness of 
egg all the cells could not be seen from one viewpoint. 
(Drawn by Nell Henry.) 
Figure 115.— Chasmodes bosquianus. From egg probably in 
the 64-cell stage; about 3H hours after fertilization. Owing 
to opaqueness of the egg the cells could not be counted accu- 
rately. (Drawn by Nell Henry.) 
Figure 114. — Chasmodes bosquianus. From egg in 16-cell stage; 
about 3 hours after fertilization. (Drawn by Nell Henry.) 
Figure 116. — Chasmodes bosquianus. From egg in rather ad- 
vanced cleavage stage; about 6 or 7 hours after fertilization. 
Owing to opaqueness of the egg only that part of the blast- 
oderm projecting above the yolk is visible from one view 
point. (Drawn by Nell Henry.) 
When the eight-cell stage is reached, all the cells are no longer visible in a lateral view, 
and they cannot be seen in a surface view, as already explained. Therefore, further 
divisions cannot be clearly observed. The blastomeres are large and prominent until 
about the 16-cell stage is reached (fig. 114). Thereafter they get smaller and flatter 
rather rapidly (fig. 115). 
