i66 



EVOLUTION AND DISEASE. 



arranged in two rows, extending along the ventral 

 aspect of the trunk in both sexes ; and in situation they 

 correspond to the course of the deep and superior 

 epigastric arteries, an extraordinary anastomosis effect- 



FIG. 88. Lemur macaco and young. (After Sclater.) 



ing a free communication between the subclavian 

 arteries at the anterior part of the thorax and the iliac 

 system of arteries at the groin. This vascular arrange- 

 ment is peculiar to mammals, and has direct relation 

 with the mammary glands. 



