44 



michog came within reach and then by a sudden dart captured it. Once caught 

 the fish is usually killed by a single bite through the spinal cord or head but 

 occasionally the tail of the fish is turned toward the mouth and the squid while 

 trying to turn the fish or to bite effectively lets it escape unharmed or slightly 

 injured. The fish is thrust end on into the mouth by the arms and the buccal 

 membranes, and the jaws work rapidly, biting out large pieces which are 

 swallowed at once without further mastication. The food is swallowed so quickly 

 that there is no time for the use of the radula, nor does the food show any 

 trace of its action. It is possible , however , that the radula is used upon 

 resistant objects. If so, it is evident that the object to be comminuted is held 

 by the palatine lobes against the upper jaw while the radula is drawn back and 

 forth over the end of the odontophore which is pressed against the food. The 

 secretion of the median salivary gland which opens at the tip of the tongue and 

 from the lateral glands which open near the ends of the palatine lobes is poured 

 upon the food as it is being comminuted. The food usually reaches the stomach 

 in pieces so large that one can scarcely explain how they were able to pass 

 through the oesophagus and the skull. There the digestible portions are partially 

 dissolved probably by the action of the fluids from the caecum, intestine, and 

 liver. The partially digested food passes into the caecum and thence into the 

 intestine and rectum for complete digestion and absorption. The indigestible portion 

 of the food is voided through the intestine and rectum. 



The reproductive system. 



In both male and female animals, the sexual gland is median and is 

 suspended from the upper wall of the posterior part of the coelom. The genital 

 duct is an unpaired, more or less convoluted and glandular tube lying in the 

 left wall of the body and extending from the level of the middle of the gonad 

 nearly to the inner opening of the funnel. 



A. Male. The male reproductive organs are the testis, the complex sperm- 

 duct, and possibly the hectocotyUzed left fifth arm. 



The testis is oval transversely and elliptical longitudinally and is attached 

 to the upper median line of the coelomic wall by a mesentery formed by the 

 peritoneum which is reflected over the organ. The testis consists of a multitude 

 of tubes placed approximately perpendicular to its surface and, on the lower side 

 of the testis, opening into a small lumen which in turn opens by a narrow 

 longitudinal slit into the coelom. The testis has a porcelain-white color that, in 

 bright sunlight , is clearly visible through the mantle and pen of the living squid. 



