312 FUNCTIONS AND INSTINCTS. 



on the inner side with a double series of sessile 

 suckers, the second pair having a membranous 

 dilatation at their apex, 1 which the animal is 

 supposed to use as a sail when it moves on the 

 surface of the sea. Some naturalists deny that 

 this animal ever uses these organs for sailing or 

 rowing, but Bosc expressly asserts, and I am 

 not aware that there is any reason to doubt his 

 veracity, that he has seen hundreds of the 

 argonauts rowing over the surface of the sea, in 

 calm days, at so small a distance from the vessel 

 in which he was sailing, that though he could 

 not catch one, he could observe all their ma- 

 noeuvres ; he further says, that they employ their 

 dilated tentacle sometimes as a sail and some- 

 times as an oar. 



When we consider how many instances are 

 upon record of Molluscans being fitted with 

 organs that enable them to catch the wind and 

 sail on the surface of the sea, 2 there is nothing 

 contradictory either to analogy or probability 

 that the argonaut should do the same, espe- 

 cially when we consider how universally this 

 idea has prevailed, from the time, at least, 

 of Pliny and Oppian, both of whom describe 

 its sails with sufficient accuracy. Aristotle also 

 speaks of his polype, which is evidently a 

 cephalopod, as a sailor by nature he says, 



1 See Zool. Journ. n. xiii, t. iii. 2 See above, p. 263. 



