136 FISHES OF SAN DIEGO—EIGENMANN. 
fully attempted. The eggs are very adhesive, and come from the ovarye ; 
in long strings. Shortly after they have been deposited they lose their 
adhesive power, and if they are then freed from the objects to which 
they have become attached they do not adhere again. 
The membrane at the time of deposition is greatly shriveled and 
does not become distended till some time afterwards. 
The yolk is collected in small spheres; it is grayish while the proto. 
plasm is yellow and collects at the side of the egg. This fact enables 
one to trace the formation of the germinal disk quite readily. In an 
hour the protoplasm is wellcollected at the ectodermal pole, while proe- 
esses extend from it over the yolk and others probably in between the 
yolk spheres. Frequently there is also a slight thickening of proto- 
plasm over the entodermal pole. The fate of this has not been deter- 
mined. Fig. 4. 
One hour and fifty minutes after fertilization one of the eggs began 
to segment. The segmentation furrow descends slowly, producing 
slight folds on the surface of the blastomeres on either side of the fur- 
row. With the descent of the furrow the blastomeres become more and 
more separated. When the furrow has reached the base of the germi- 
nal disk it slowly closes up again, the blastomeres becoming closely 
appressed. At one hour and fifteen minutes from the beginning of the 
first segmentation the second furrow appears. At one hour and forty- 
five minutes the third cleavage has been completed in several eggs. (Fig. 
15.) Itisnow seen that the segmentation is not quite symmetrical, and 
the third cleavage, which invariably leaves eight cells in pelagic eggs in 
this case, produces five or six or seven as well as eight, and these are 
not very regularly arranged. This fact is undoubtedly due to the has- 
tening of the segmentation in some cells and the retardation in others. 
The development of this species does not differ greatly from that of 
the shad, and the accompanying figures probably sufficiently illustrate 
the different stages. 
The meridian of the embryo comes to lie in a horizontal plane. 
Two days after fertilization the embryo begins to move and the heart 
beats. 
Six days and a half after fertilization one of the membranes was 
empty, but the fish could not be found. The remaining embryos 
remained active in the shells five days longer when all of them died. 
The larvee or young of this species I have never found. 
Clupea sagax Jenyns. 
J. & G., ’80, 30; R. Smith, ’80; J. & G., ’80a, 457; id.,’81, 37; id., ’82, 265; R. 
Smith, 785, July. 
This species enters San Diego Bay about the first of September 
(large ones were first seen the past season on September 10) and 
remains till some time in March. Large schools of them are found — 
about the wharves. Few are caught in seines, and many of these are— 
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