THE PAST AND PRESENT OF THE CUTTLEFISHES. 91 



connection with their general structure and physiology. Any one 

 who has attentively watched the movements of an octopus in its tank 

 must have been struck by the literally acrobatic ease with which it 

 accommodated itself to the exigencies of its life and surroundings. In 

 their lithe, muscular, and flexible arms, the cuttlefishes possess an 

 apparatus which is equally serviceable for the capture of prey, and 

 for walking mouth downwards that is, in their structurally natural 

 position. They possess, likewise, the power of swimming upper side 

 forwards or popularly stated " backwards " by means of the jets of 

 water which, by forcible contractions of the muscular mantle-sac, are 

 projected from the tube or " funnel," situated on the hinder face of 

 the body. These jets d'eau consist of the effete water which has 

 been used in breathing, so that the act of expiration and the effete 

 water of respiration together become utilised, in the economical 

 wisdom of nature, as a means of propulsion. The mysterious back- 

 ward flight of an octopus through its tank (fig. 5) when, detaching 

 itself from its hold on the rock, it swims gracefully and swiftly 

 through the water, is effected in the manner just described. This 

 form of hydraulic apparatus, imitated in experiments in marine en- 

 gineering, serves but to strengthen the wise man's adage concerning 

 the utter lack of novelty in terrestrial and mundane things. 



It is equally interesting to note that some of the squids or loligos 

 named popularly "flying squids" appear to be able to rise from 

 the surface of the sea and to spring into the air after the fashion of 

 the flying-fishes. Pliny, in his " Natural History," says, " Loligo 

 etiam volitat, extra aquam se efferens, quod et pectunculi faciunt 

 sagittse modo ; " whilst Varro insists that the name "loligo " is itself 

 a corruption of " voligo." The initial velocity of these cuttlefishes, 

 acquired by their rapid propulsion through the water, enables them 

 thus to career for a short distance through the air. Instances are 

 mentioned of the flying squids having occasionally landed them- 

 selves on the decks of ships in their atmospheric leaps. 



The " arms " or " feet " demand, however, a somewhat detailed 

 mention, on account of their armature. In all cuttlefishes, save the 

 exceptional pearly nautilus, the arms are either eight or ten in 

 number, and are provided with acetabula, or " suckers." Those 

 cuttles in which ten arms are present and of these the squids and 

 sepias form good examples have two of these appendages produced 

 beyond the remaining eight in length. Aristotle noted in his day 

 this peculiarity of the ten-armed cuttles. Speaking on this point, he 

 remarks that all of these animals "have eight feet provided with a 

 double series of suckers, except in one genus of Polypi " the genus 

 Eledone, in which there is but a single row of suckers. " The sepia, 

 teuthides, and teuthi (that is to say, the sepias and squids) have 

 besides two long probosrides, the extremities of which are beset with 



