414 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
To show their position in the ovary I have tabulated the following series : 
Total 
No. of 
young. 
Size. 
No. in 
ovarian 
sacks. 
No. be- 
tween ova- 
rian sacks 
and ova 
rian walls. 
Axis cor- 
responding 
to that of 
mother. 
Axis re- 
versed to 
that of 
mother. 
n 
18 mm. 
3 
8 
g 
3 
14 
21 
6 
8 
6 
8 
• 12 
20 
4 
8 
3 
9 
11 
6 
5 
6 
5 
17 
40 
16 
14 
1 14 
10 
4 
10 
32 
3 
12 
18 
5 
7 
From this it is evident that there is no definite arrangement of the larvse as far 
as the ovarian sack is concerned, and scarcely any as far as the axis of the embryo is 
concerned, but the condition indicated by the larvae 40 mm. long in the above list is 
repeated in all the largest larvae. That is, when they approach the period of extru- 
sion they come to lie with their heads forward. This may be due to the fact that the 
gills being now well formed the heads of the larvae are turned to the origin of the 
oxygenated blood supply, which is at the anterior end of the ovary. 
Intraovarian food . — The yolk, both on account of its small size and because it is 
not absorbed until very late, is evidently not sufficient to account for the growth of 
the embryo and larva. It disappears months before the intraovarian development is 
complete. There is probably general surface absorption through the whole of the 
ovarian life and, as we shall see, there is evidently intracellular digestion in the epi- 
dermal cells in the eggs. The yolk is scarcely if at all diminished before the zona bursts, 
and yet growth is so rapid that the mere size of the embryo bursts the zona long before 
auy movements are evident on the part of the young. This process of absorption by 
the general surface practically supplies all the food until the first gill-slit is open. 
With the opening of the first gill-slit a new process begins — the absorption by the 
intestinal canal. Before the mouth is opened a continuous stream of the fluid contents 
of the ovary enters the first gill-cleft, and passes apparently unchanged through the 
anus. This process can frequently be observed. 
This continuous stream is due to the presence of cilia in the intestinal tract. 
The blood corpuscles and solid particles of the ovarian fluid seem to get into small 
whirlpools if they approach the side of the tract. Part of this may be due to the 
presence of spermatozoa, which frequently fasten themselves in clusters on the inner 
surface of the intestinal tract while their tails are kept in active vibration. The 
spermatozoa remain in the ovary during several weeks of gestation. 
In one individual the stream into the gill-cleft was especially noticeable, as the 
stream contained many blood corpuscles which had been freed when the ovary was 
slit open and a large number of highly active spermatozoa. With the opening of the 
mouth long villi appear in the hind gut, and the process of digestion proper is estab- 
lished. Soon after this the spermatozoa disappear from the ovarian fluid, being in all 
probability digested in the hind gut. Succeeding the opening of the mouth, a solid 
mass of substance is frequently found in the intestines, which is composed of the solid 
particles of the ovarian fluid and which in part is composed of these spermatozoa. 1 * 
* In my first, notice of this fish I did not know the meaning of the mass nor did I then know that 
food is taken in through the hyomandibular slit before the mouth is open. 
