ELEDONE. 487 
to any object, the extensor relaxes, the sphincter 
contracts, and the massive muscular base of the inner 
chamber is elevated to meet the sphincter. Thus we have 
a shallow flattened disc-like surface pressed closely 
against the object to be held. Now the extensor contracts 
and the sphincter relaxes a little, and the floor of the 
inner chamber is drawn away from the object, producing 
the desired vacuum. 
All Cephalopods have power to regenerate injured 
arms. Frequently specimens of Hledone have been seen 
with several arms in process of regeneration. When an 
arm is first injured, it is curled up spirally towards the 
mouth so as to protect the injured part. 
b. So nn - BIO OF FASS S FOF GIES 
Fie. LVY.—(a) Hectocotylised arm and (d) ordinary arm of male 
H. aldrovands. x 2. 
Hectocotylisation.—The third right arm of the male 
Eledone is hectocotylised, i.e, 1t is modified for the 
purpose of transferring the spermatophores expelled from 
the anterior opening of the funnel into the oviduct of the 
female. As no male LH. cirrosa could be obtained, Text 
fig. IV a, shows the hectocotylised arm of a young 
male #. aldrovandi, which is very similar. Some 
Cephalopods have an autotomous hectocotylised arm, e.g. 
Argonauta and Tremoctopus, and in these hectocotylisa- 
tion reaches its extreme state of specialisation. 
Spermatophores having been expelled from the funnel of 
