3 68 



VESSELS OF THE SPLEEN. 



[sect. 169. 



The main trunks of the splenic artery, after its entrance into 

 the spleen, immediately divide into a large number of branches 

 in an arborescent manner, the larger branches proceeding to the 

 anterior, the smaller to the posterior border of the organ. There 

 is no anastomosis between the main branches of this artery. When 

 they have become attenuated to jf" to ^" in diameter, they separate 

 from the veins, with which, hitherto, they have been covered in the 

 sheaths, and become connected by fine twigs with the Malpighian 

 corpuscles in the manner already described. These small arteries are 

 frequently attached firmly to the surface of the corpuscles, but I 

 have never seen them pass through them, as J. Midler formerly 

 supposed. They enter the red splenic substance, and immediately 

 break up into beautiful tufts of very small arteries, the so-called 

 penieilli (fig. 155), which then partly enter into the Malpighian 



Fig. 155. 



An artery with its tufted termination, from the spleen of the pig; magnified 25 times. 

 After an injection by Gerlach. 



corpuscles (see above, § 167), partly break up independently into 

 true capillaries, 0-003'" to 0-005"' m diameter. These capillaries 

 join in a widish mesh work, which surrounds the Malpighian cor- 

 puscles, and extends throughout the entire parenchyma. 



With regard to the veins of the spleen, I am anxious, in the 

 first place, to deny the existence of venous spaces (sinus venosi), 

 described by both older and more modern anatomists, in the human 



