656 THE AMERICAN NATURALIST. | [Vor. XXXIX. 
in the beginning, and the sex plainly marked, the eggs being 
ovoid bodies, about two millimeters long and the sperm spheres 
larger than before. 
Only between twenty and thirty egg cells develop into mature 
ova during one cycle, many of those starting development being 
arrested when from two to six or eight millimeters long, and 
the other spheres failing to develop. Whether this applies to 
the sperm spheres could not then be ascertained. No new facts 
were observed relative to the question of hermaphroditism. 
This condition was not present in any of the relatively few fish 
examined by me. 
The hagfish oviposits at all seasons of the year, but probably a 
great many more mature in the spring than at any other season ; 
and I think that no individual deposits eggs more than once a 
year, perhaps not so often as that. Of those studied by me be- 
tween July 1 and October 30, about half were in the resting 
stage where it was impossible to detect sex difference. Among 
the others I did not find any fully ripe male; of the females 
only two had reached maturity, and of these but one produced 
ripe eggs, while the other died from some unknown cause before 
the eggs were deposited. The eggs are easily felt through the 
thin body wall in handling the fish, and I had from ten toa 
dozen fish with very large eggs under observation for six weeks 
or more, but the time was not sufficient to bring more than the 
one fish to the point of ovipositing. 
The supposition that the greater number of hagfish breed in 
the spring is also supported by the relative numbers of eggs 
found at different times of the year. Embryos can be found at 
any time in various stages of development, but most of those 
taken even in September are small. - 
Of thirty-seven embryos gathered between September 8 
and September r5, eleven were too small to be taken from the 
shell, eleven more were less than 30 mm. long, six were between 
30 and 40 mm., seven between 40 and 50 mm., one 54 mm., and 
one 65 mm. This last was evidently within a short time of 
hatching, as it swam freely when taken from the shell. During 
this same week only four recently hatched hagfish were brought 
in, and of these one was 60 mm., one was 80 mm., and one 83 
