380 GILMAN A. DREW 
with the Biological Department of that university, and I am 
grateful for working space furnished me by the University of 
Arizona during the winter of 1917. By far the greater part of 
the work has been done at the Marine Biological Laboratory 
at Woods Hole, Massachusetts, and all of the material has been 
obtained at that station. 
This species of squid is very abundant in the vicinity of Woods 
Hole, and any mature male taken from early in the spring until 
as late as September, and frequently later than that, is sure to 
have an abundance of spermatophores in the spermatophoric 
sac. 
The spermatophores vary in size according to the size of the 
animal from which they are taken. Those from very small 
animals may not be over 8 mm. in length and those from large 
animals may be as much as 16 mm. in length. They are of 
course all similar in structure, but the small ones are softer and 
are not so easily handled in ejaculation observations as the larger 
ones. As might be expected, there are some slight individual 
variations in shape and size of parts in the spermatophores of 
different individuals. The spermatophores of each individual 
are practically identical in shape and appearance, but may 
vary slightly in size. 
The number of spermatophores carried by each individual 
varies with the size of the animals (the smaller having fewer than 
the larger), with the season of the year, and with the frequency 
of copulation. May and June are probably the months when 
sexual activity is at its greatest. Usually at this time the sper- 
matophoric sacs are gorged with spermatophores. A large 
individual may have as many as four hundred fully formed 
spermatophores stored at one time. 
The formation of the spermatophores is evidently rather 
rapid. Several, perhaps several dozen, may be formed in a day. 
It is difficult to determine with anything like accuracy what 
the rate may be, but after a male has used large numbers of sper- 
matophores in repeated copulations, a day or two is sufficient to 
bring the supply almost if not quite to normal. 
