INSECTA 



119 



by the teeth and strained by the setae before being introduced 

 into the enteron. 



The enteron, or chylific ventricle, is the region where digestion 

 is completed, and where absorption of the food takes place. 

 It is like the intestine which follows it, but is marked in front 

 by the club-shaped digestive glands, and it ends just in front 

 of the filamentous Malpighian tubules. The opening of the 

 gizzard projects into the anterior end of the enteron, and it is 

 here that the food receives the digestive fluids containing 

 enzymes from the tubes of the digestive gland. These 



Sub-oesophageal 



ganglion Salivary 



Cerebral 

 ganglion 



Tracheal 

 system 



Right 



ovary Spermatheca 



Gonapophyses 



Tibia 



Rectum 



Tarsus 



Stomach 



ffalpighian 

 tubules 



Colleterial 

 gland 



Hepatic 



FIG. 58. Blatta. Diagram illustrating the general anatomical structure of 

 a female. The thoracic and the abdominal terga are numbered. 



act upon the food and resolve the soluble part into a solution 

 containing peptones, sugars, salts, and an emulsion of fats. 

 These are absorbed by the endoderm cells and passed into 

 the blood. The residue is carried along the intestine to be 

 discharged or egested. 



The proct odeum, or intestine, is marked at its origin by the 

 Malpighian tubules, and its forward part has been called the 

 ileum, the middle the colon, and the terminal wider part the 

 rectum. 



Respiratory Organs. Eespirat ion takes place by tubular 

 invaginations of the skin called tracheae, and their openings 



