CIRCULATORY SYSTEM. 133 



larger than white blood-corpuscles, are mononu- 

 cleated and contain pigment and frequently red 

 blood-corpuscles. 



Blood Supply. The splenic artery enters the hilum 

 and its branches follow the trabeculae. Ultimately 

 the smaller branches enter the spleen pulp. Beyond 

 the Malpighian bodies the smaller arteries end in 

 minute dilatations known as the ampulla of Thoma. 

 Beyond these the blood flows directly into the meshes 



Fig. 97. From the human spleen (chrome-silver method) (Bohm and 

 Davidoff). 



of the spleen pulp with no other walls than the spleen 

 cells. The veins begin in the same way as the 

 arteries end. The capillary veins pass directly to 

 the trabeculae and ultimately unite at the hilus to 

 form the splenic vein which drains into the portal. 



General Considerations. The invasion of bacteria 

 into the system is chiefly along the lymphatics. 

 Each lymph node becomes a point of resistance, and 



