44 CRUSTACEA. 



large particle to enter the delicate tube of the intestine. 

 Opening into the pylorus on either side are the large 

 yellowish-green lobes of the liver. The straight in- 

 testine traverses the whole length of the abdomen, and 

 ends in the last segment, like the intestine of the 

 worm. 



On removing the digestive ^vstcm, two large organs 2 

 remain, which an- dark green in the uncooked lobster, 

 and red in the boiled specimen. These are the ovaries, 

 which Open on the basal joints (Fig. 8, />', <• 3. z) of 

 the third pair of walking-legs. The eggs come out 

 of these two openings, and are surrounded with a 

 sticky substance, by which they become fastened to 

 the hairs of the swimmcrets. I [ere they remain till the 

 young are hatched. If the lobster is boiled before 

 the eggs are laid, they turn red. and are known as " the 

 coral," from their resemblance to coral beads. The 

 reproductive organs of the male are smaller and longer 

 than those of the female, and open on the basal joints 

 of the last pair of thoracic appendages ( Fig. 7, z). 



Thus not only the external parts of rings, but nearly 

 all the vital organs of the lobster, are concentrated in 

 the cephalothoracic region. Even the generative or- 

 gans have been crowded forward, so that the abdomen 

 is really little more than a tail, or muscular organ, for 

 propelling the animal through the water. This being 

 the case, some naturalists prefer to call it the "tail." 

 or " post-abdomen ; " but these names involve the 

 scholars in difficulties when they begin to study insects, 

 so that it seems desirable to retain the name of abdo- 

 men, at the same time bearing in mind its tail-like 

 function. 



