658 THE AMERICAN NATURALIST. | [Vor. XXXIX. 
tological purposes, the embryo is generally so much hurt that it 
will not develop further but must be fixed at once. 
Hagfish embryos are exceedingly slow in developing. The 
evidence pieced together from the eggs brought in and the 
statements made by the fishermen as to the seasons when cer- 
tain sizes of embryos were most easily found, was confirmed by 
the development of the seven eggs laid in the aquarium. 
The average egg when laid is about twenty-three millimeters 
long (though some are shorter by several millimeters), and about 
six millimeters broad at the broadest place. The opercular ring 
is three millimeters from the animal pole (Fig. 5, 2). Very rarely 
a second ring is found at about the same distance from the vege- 
tal pole. 


Fic, 5.— i 1 : 
IG. 5.— Eggs in the early stages of development. a, fresh laid egg; 4, the same egg with 
th 
mal pole; c, three- 
_ Dean ('99) speaks of the egg being encased, when deposited, 
in two outer membranes, both of which are shed shortly after 
laying. Several eggs were brought me by the fisherman that 
had evidently been secured before they were ripe for oviposition. 
These eggs were identical with those, mentioned above, that I 
