THE DEVIL-FISH OF FICTION AND OF FACT, 27 



The author accurately describes the action and movement of 



the octopus, and its utiHsation of its eight arms when crawHng at 



the bottom, or on ledges of rocks. The globose body is then 



turned upward, the mouth downward, and the arms sprawl along, 



and by grappling some fresh object drag the body after them. 



But he is mistaken concerning its mode of progression when 



swimming. After stating that in swimming, it, so to speak, 



sheaths and draws close together its arms, which is quite true, he 



continues : — 



'* Figure to yourself a sleeve sewn up with a fist in it. This fist, wJiich is the 

 head, pushes through the water, and advances with an undulating movement." 



That which M. Hugo supposes to be the head is the body of 

 the animal. He appears to have received this impression from 

 Pliny,* who writes : — " The head, which is directed obliquely 

 when they swim, is, in the living animal, hard and distended like 

 a balloon." The cuttle-fishes, and the octopus amongst them, 

 propel themselves rapidly backward, when swimming, by the 

 forcible expulsion from the funnel, in sudden and frequent jets, of 

 the water drawn in at the branchial, or gill openings. Thus the 

 organs of respiration become those of locomotion as well, and the 

 funnel has also another function, being the orifice from which the 

 excreta are expelled. It has been asserted by various writers — 

 and the statement has been repeated by many able naturalists — 

 that the octopus swims by vigorous flappings of the expanded 

 membrane which extends from the sheath of the mouth along the 

 arms, and connects the bases of the latter like the web of a duck's 

 foot It is true that this sometimes, though very rarely, takes 

 place, but its proper and usual mode of progression is with the 

 body in advance, the arms closely packed together, and directed 

 backward horizontally in its wake, whilst the jets of water, 

 pumped out at frequent intervals from the funnel, propel it at 

 a considerable speed. I have had opportunities of watching the 



* " Naturalis Historic," lib. ix. , cap. 29. 



