SEXUAL ACTIVITIES CF THE SQUID 331 
ing dises somewhat smaller, but in none of the suckers of this row 
are the sucking dises entirely absent. A glandular plaited ridge 
extends lengthwise between the suckers of this region and gives 
off branches that join each of the peduncles. This ridge is highest 
and broadest opposite the suckers that are most modified and grad- 
ually disappears as the suckers become normal. At its highest 
point it has about the same elevation as the shortest modified 
suckers, which are adjacent. Sections of the modified portion of 
the arm show that the ridge and suckers mentioned are covered by 
a thick columnar epithelium that stains deeply. Many of these 
epithelial cells are filled with large rounded granules that stain 
with eosin. The cells that cover other portions of the arm are 
flattened or cubical, do not stain very deeply, and do not contain 
granules. It seems probable that the cells of the hectocotylized 
region secrete a substance that aids the arm in holding the sperm- 
atophores. The modified suckers probably make the bending 
and grasping necessary for the transfer of the spermatophores 
more easily accomplished. 
The positions of the animals during copulation are rather hard 
to determine as the whole process generally does not occupy more 
than ten seconds and during this time the animals are usually 
swimming and the arms are changing positions, but by carefully 
focusing attention during different acts upon first one arm and 
then another, the positions and movements have been determined 
with some accuracy I think. Fig. 1 represents the positions of 
the animals while the arm of the male that bears the spermato- 
phores is inserted into the mantle chamber of the female. This 
figure is the result of my conception of positions after having care- 
fully observed copulation more than twenty times. Since draw- 
ing the figure many other observations have been made and the 
positions always seem to be essentially as given. 
The male usually grasps the female while both are swimming. 
Occasonally the female may be resting on the bottom in the charac- 
teristic attitude, with the tips of the arms and the posterior 
_ end of the body touching and the head and funnel region somewhat 
elevated. If not swimming, she usually, when grasped, starts 
to swim, but in a few cases that I haveobserved she made no effort 
