XIV 



THE LYMPH 



547 



which cover them with an adventitious lyniphoid sheath. In the 

 small arteries this sheath dilates here and there into grey nodules, 

 oval or spherical, of various sizes (1-0*36 mm. in diameter), similar 

 in structure to the solitary follicles of the intestine, and known as 



U 



FIG. 260. Thin section of splenic pulp near the origin of a small vein, highly magnified. (E. A. 

 Schafer.) y, Venule filled with red and white blood-corpuscles ; bl, erythrocytes which fill 

 the interstices of the reticular tissue of the pulp ; p, branching connective-tissue cells which 

 form the reticulum containing the pulp. 



Malpighian nodules or corpuscles, after their discoverer. These 

 nodules, for the most part, develop laterally to the small arteries, 

 from which they receive twigs that irrigate the follicular tissue 

 (Fig. 261). Under 

 the high power, each 

 Malpighian corpuscle 

 shows a complex reti- 

 cular structure, by 

 which they are differ- 

 entiated from the 

 honionynious tissue of 

 the splenic pulp (as 

 shown in Fig. 262, 

 which represents a 

 preparation obtained 

 by the silver chromate 

 method). 



The small arterial 

 rarni, after leaving the 

 trabecular tissue and 



FIG. 201. Small splenic artery (dog), with many Malpighian 



shea 



corpuscles attached to the perivascular lymphatic sheath ; 

 magnification of 10 diameters. (Kolliker.) 



penetrating theareolar 



labyrinthine tissue which contains the pulp, divide into small 

 feathered tufts of arterioles; they afterwards lose their tubular 

 form and continue, in the opinion of most histologists, not in 

 the usual way by a closed capillary network into the veins, 



