DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
609 
in general bad become smaller and more numerous. Tbe heart was beating rapidly, 
sending the blood to the body through a large vessel situated near the ventral outline. 
This artery left the embryo somewhat more than an eye’s diameter from the tip of the 
tail where it entered the yolk and divided into several branches. These branches all 
coursed over the yolk and in a general way ran toward the snout of the embryo, 
underneath which the heart is situated. There they united just before pouring their 
contents into the heart (fig. 119). 
On the fifth day of incubation, with the temperature of the water still remaining 
near 26° C., the embryo had encircled the egg. The tail reached opposite the head. 
It was free and moved frequently. The eyes were very prominent, being fully pig- 
mented, and visible without magnification. The yolk was reduced to about two-thirds 
its original size and more or less crescent-shaped, having been cut into very deeply in 
the head region of the embryo. Oil globules of various sizes remained distributed 
throughout the yolk. The central opaque body, previously described, and still visible 
a day or so earlier, had disappeared. Dark markings on the yolk had become more 
Figtjre 119 . — Chasmodes bosquianus. From egg with devel- 
oping embryo; 4 days after fertilization. Arrows indicate 
the direction of the flow of blood in the larger vessels. 
(Drawn by Nell Henry.) 
Figure 120. — Chasmodes bosquianus. From egg with ad- 
vanced embryo; 6 days after fertilization. H, heart. Arrows 
indicate direction of flow of blood in the larger vessels. 
(Drawn by Nell Henry.) 
numerous and in general smaller. They now consisted mostly of lines branching 
more or less from a central point, and many of them were shaped somewhat like 
crow’s feet. A concentration of dark markings was taking place in the trunk region 
of the embryo. Circulation was brisk, and the blood returned within the embryo, 
the caudal vein being quite fully developed. Corpuscles were distinct, and the heart 
and large vessels near it had a pinkish tinge (fig. 120). 
Development progressed slowly after about the fifth day of incubation. By the 
seventh day, with a drop in temperature to 24.5° C. between the sixth and seventh 
day, the tail of the embryo reached a little past the head. The embryo was capable 
of considerable movement, carrying the yolk with it as it turned in the egg case. 
The yolk had been cut into more deeply and was definitely crescent-shaped. The black 
markings on the yolk, described in the foregoing paragraph, although variable in 
number in different eggs, had become less numerous, and a further concentration of 
black had taken place in the trunk region of the embryo. Also an irregular black 
blotch was present at each auditory vesicle. Almost innumerable blood vessels were 
