6 



ZOOLOGY 



particular kind of work (cf. Fig. 5). The food of the cricket 

 consists of various sorts of animal and vegetaljle debris, — old 

 fragments of meat, pieces of cloth or paper, fallen fruit, etc. 

 Bits of suitaljle size are torn off by the mandibles and carried 

 to the gullet, where they are wet bj- the saliva. They then 

 pass into the crop, an enlarged part of the tube, where the 

 hard food is held and worked over until it is softened by 

 various juices secreted by the glands. The food then passes 



Fig. .5. — Longitudinal section of fomalo cockroarh to show ]:tosition 

 of jjrinr'ipal organs, Oe., oesophagus ; .S. gj., salivary gland ; .S'. r., 

 sali\'arj' reservoir ; Cr., crop ; (?., gizzard ; .SV., stomacli ; i?.. rectum ; 

 Hi., heart ; N.C., nerve cord, x .5. After iMiall and Denn\'. 



to the third part of the tulje, the stomach. Between crop and 

 stomach a number of sacs open which secrete the digestive 

 juices. From the stomach the digested food goes into a long 

 plain tube — the intestine — through the walls of wliich the 

 soluble portions pass and mix with the fluids of the bodj'. 

 Finally the indigestilde portions collect in the hinder part of 

 the tul^e to be from time to time expelled. 



Respiration in the cricket is effected by a very different 

 mechanism from ours. From the spiracles on the rings of the 

 abdomen and the thorax pairs of tuljes called trachcce enter the 

 Ijody and divide again and again, going to the main muscles of 

 the back, to the food-canal and reproductive organs, and to the 



