SEXUAL ACTIVITIES OF THE SQUID 381 
STRUCTURE 
Each spermatophore consists of a white opaque mass of sper- 
matozoa surrounded by almost transparent liquids and mem- 
branes, a mass of material, rather opaque but not so opaque as 
the mass of spermatozoa, which lies against one end of it, and 
a brownish spiral filament together with a number of membranes 
of varying degrees of transparency on the other side of the body 
just mentioned. For convenience we may speak of these main 
divisions as the sperm mass (fig. 1, SM), the cement body (CB) 
which lies at one end of the sperm mass and was called by Raco- 
vitza the ‘faux boyaux,’ and the ejaculatory apparatus (HA), 
composed of the complicated group of membranes and the spiral 
filament which joins the cement body and occupies the smaller 
end of the spermatophore. It is also convenient to speak of 
the portion of the spermatophore occupied by the ejaculatory 
apparatus as the oral end, since from this end ejaculation takes 
place. 
Figure 1, a complete spermatophore, shows that the aboral 
is considerably larger than the oral end. The sperm mass is 
little more than half the diameter of the spermatophore and does 
not extend to the extreme aboral end of the spermatophore. 
There is some difference in the amount of space posterior to the 
sperm mass, and likewise in the diameter of the portion of the 
spermatophore in which the sperm mass lies in different sper- 
matophores. This is due largely to the fact that the spermato- 
phores, when liberated take up water rapidly, and consequently 
swell and change in shape. This condition is easily controlled 
by passing the spermatophores into solutions of formaldehyde. 
Full strength formaldehyde will do no harm, but 10 per cent 
formalin is sufficient for ordinary purposes. 
In studying the structure I have found that staining the forma- 
lin-treated spermatophores in dilute solutions of Ehrlich’s triple 
stain or in Ehrlich’s triacid stain and mounting in glycerin 
jelly has been very helpful. The stains are selective and stain 
different parts different colors or shades. The glycerin jelly 
will clear and preserve without shrinking the specimens badly. 
