342 GILMAN A. DREW 
ity of this animal is very great, for a great mumber of young are produced 
from itsova. The male differs from the female in having a longer head, 
and the part of the tentaculum which the fishermen call the penis is white. 
It incubates upon the ova it produces, so that it becomes out of condition, 
and is not sought after at this season. 
Part of these statements, such as “‘The sepia and loligo swim 
about coiled together in this way, and with their mouths and ten- 
tacula united, they swim in contrary directions to each other’ 
would seem to be based upon such observations as could be made 
from above but the further statement that they adapt their nos- 
trils (funnels) together, probably indicates the ease with which 
observation and supposition can be mixed. It is not necessary 
further to analyze Aristotle’s statements. No doubt much was 
based upon fishermen’s stories but he evidently did study the an- 
atomy and habits of these animals and recognized the probability 
that one of the arms of the male is used in copulation. 
While the modified arm of the male thus early received atten- 
tion, the true hectocotylus that separates entirely from the male 
and attaches itself in the mantle chamber of the female escaped 
notice for many centuries. To quote from the Cambridge Natural — 
History: 
The typical hectocotylus seems to have entirely escaped notice until 
early in the present (last) century, when both Delle Chiaje and Cuvier 
described it, as detected within the female, as a parasite, the latter under 
the name of Hectocotylus octopodis. Kd6lliker, in 184549 regarded the 
Hectocotylus of Tremoctopus as the entire male animal, and went so far 
as to discern in it an intestine, heart, and reproductive system. It was 
not until 1851 that the investigation of Vérany and Filippi confirmed a 
suggestion of Dujardin, while H. Miller in 1853 completed the discovery 
by describing the entire male as Argonauta. 
While nearly all male cephalopods show some modification of 
one or more arms, the only ones that have been reported with de- 
tachable arms are Argonauta, Ocyth6ée, and Tremoctopus. 
Extended studies have been made on the modification of the 
arms of cephalopods, and there have been a few observations upon 
