is BRITISH ANTS. 



food it contains is used to feed the brood, and the other ants of the 

 colony, by regurgitation. 



The gizzard connects the crop with the stomach proper, it has 

 been called the pumping-stomach, is very variable in form, and 

 affords valuable characters, which can be used to differentiate 

 genera and even sub-families. It is composed anteriorly of a cup- 

 shaped portion, the calyx, the chitinous walls of which are formed 

 by eight bands, the four thicker ones, the sepals., contract at their 

 posterior end to form a valve. The gizzard then becomes dilated 

 into a bulb, the pumping-stomach proper ; this is followed by a 

 cylindrical portion which enters the true stomach, where it termin- 

 ates in a knob-shaped valve. The walls of the gizzard, and especi- 

 ally the bulb, are provided with very powerful muscles. The 



Fig. 33. Gizzard of Tapinotna erraticum ^ (anterior view). 



gizzard is more simple in the Ponerinae, and Myrmicinae, and more 

 complicated in the Dolichoderinae than in the Camponotinae. 



The stomach proper is a sac in which the food it receives is 

 digested, it is not capable of much distension, and does not possess 

 any chitinous lining. 



The intestine is a more or less wrinkled tube which connects the 

 stomach with the rectum, and near its anterior end where it forms 

 a valve, the Malpighian tubes or urinary vessels are inserted. 



The rectum is large, tapering towards its posterior end where it 

 terminates in the anus ; in it the faeces and urinary excretions 

 are collected. 



The anus varies in shape in different genera, it is provided with 

 a sphincter muscle, and is sometimes fringed with hairs. 



The Glands. 

 1. Glands in the Head. 



The antennary glands consist of a few cells, the slender ducts of 

 which open on a small space, situated in a depression at the base 

 of each antenna. 



The maxillary glands comprise two groups of cells placed above 



