60 



MANUAL OF THE APIAKT. 



vivifying air, and are thus called rat-tailed. Even the pupae 

 of the mosquito, awaiting in its liquid home the glad time 

 when it shall unfold its tiny wings and pipe its war-note, 

 has a similar arrangement to secure the gaseous pabulum. 



The digestive apparatus of insects is very interesting, and, 

 as in our own class of animals, varies very much in length and 

 complexity, as the hosts of insects vary in their habits. As 

 in mammals and birds, the length, with some striking excep- 

 tions, varies with the food. Carnivorous or flesh-eating in- 

 sects have a short alimentary canal, while in those that feed 

 on vegetable food it is much longer. 



Fig. 9. 



Alimentary Canal. 



o— Honey Btomacb. 

 c — Urinary tubes. 



&— True stomach. 

 <i— Intestine. 



The mouth I have already described. Following this is the 

 throat or pharynx, then the oesophagus or gullet, which may 

 expand, as in the bee, to form a honey or sucking stomach 

 (Fig. 9, o), may have an attached crop like the chicken, or 

 may run as a uniform tube as in our bodies, to the true stom- 

 ach (Fig. 9, b). Following this is the intestine — separated 

 by some into an ileum and a rectum — which ends in a vent 

 or anus. In the mouth are salivary glands, which in larvae 

 that form cocoons are the source of silk. In the glands this 

 is a viscid fluid, but as it leaves the duct it changes instantly 



