On the Spermatophores of Octopus Americana. 39 
phore of the squid. The difference in the strength and stretch of the 
outer tunics and in the osmotic properties of the middle tunics is doubt- 
less responsible for the difference in rapidity of ejaculation in the two 
forms. The whole process is usually complete in less than 10 seconds 
in the squid and may occupy from 1} to 3 minutes in Octopus. 
The liquid that occupies the space between the sperm mass and 
the ejaculatory apparatus is continued along the sides of these two 
portions between them and the outer coverings, so there is no adhesion 
between them and the outer tunic or middle tunic except where the 
ejaculatory apparatus is permanently attached to the outer tunic at 
the oral extremity. The liquid that occupies this space is not so 
absolutely transparent as it is in the squid spermatophore, but is 
noticeably granular throughout. It is much more granular in the 
space between the sperm mass and ejaculatory apparatus, but nowhere 
is it entirely free from granules. 
Along the sides of the sperm mass the space occupied by the liquid 
is always distinct (fig. 1 st). Along the sides of the ejaculatory appa- 
ratus it is frequently hard to find except in the grooves between the 
loops of the spiral into which a portion of it is thrown (fig. 3 st). 
Ejaculation shows, however, that there are no adhesions at any 
point and that the liquid serves as a lubricant and to transmit pressure 
during the act. 
The sperm mass (fig. 1 sm) consists of a thread of sperm, mixed with 
a somewhat granular viscid secretion, that is wound into a cylindrical 
spiral. The separate loops, unlike those of the squid sperm mass, are 
distinct with the outlines rounded. The loops are not compressed 
against each other enough to flatten their adjacent sides very much 
and the mass is not inclosed in an inner tunic. That the inner tunic 
is completely absent in this form is indicated by the fact that when 
ejaculation begins the sperm thread begins to uncoil and straighten 
(fig. 16 sm). This would not be possible if the sperm mass were 
inclosed in a definite tunic, as is the case in the squid. 
The sperm thread is not of entirely even diameter throughout and 
the coiling is not entirely regular, but the irregularities are only 
imperfections and have no functional significance. 
The sperm mass is usually referred to by authors as the sperm rope. 
In using this term it should be borne in mind that unlike a rope it con- 
sists of but a single coiled strand. 
The ejaculatory apparatus, while easily compared with that of the 
squid, differs in the absence of the inner tunic and outer membrane 
and in its end relationship, for this form has no cement body. It is 
perhaps questionable whether there is an outer membrane, but I have 
not been able to distinguish one. The middle membrane is thick, 
evidently very pliable, and (as in the case of the squid) is composed 
of many thin longitudinal layers that are presumably due to the 
