MIXUTE STRUCTUEE OF THE SPLEEX. 



885 



colour and highly elastic. It cannot be raised from the spleen, because it is 

 bound down by the trabeculae of the substance, with the superficial bands 

 of which it is continuous. Along the hilus this coat is reflected into the 

 interior of the spleen, in the form of elastic sheaths or canals, which sur- 

 round or include the large blood-vessels and nerves, and their principal 

 branches. These sheaths ramify with the vessels which they include, and 

 their finer subdivisions are continuous with the trabecular structure. The 

 arrangement of the elastic sheaths and trabeculse may be easily displayed by 

 pressing and washing out the pulp from a section of the spleen ; and then 

 they are seen to form a close reticulation through the substance. Thus, 



Fig. 619. 



Fig. 619. VERTICAL SEC- 

 TION OF A SMALL SUPER- 

 FICIAL PORTION OF THE 

 HUMAN SPLEEN (from 

 Kolliker). 3 ' g 



A, peritoneal and fibrous 

 covering ; b, trabeculse ; 

 cc, Malpighian corpuscles, 

 in one of which an artery 

 is seen cut transversely, in 

 the other longitudinally ; 



d, injected arterial twigs; 



e, spleen-pulp, with the 

 venous spaces and the 

 finest spleen - tissue, the 

 venous spaces all com- 

 pletely full of blood and 

 somewhat wider than na- 

 tural. 



the proper coat, the 

 sheaths of the ves- 

 sels, and the trabeculse, 

 all of a highly elastic 

 nature, constitute a distensible framework, which contains in its inter- 

 stices or areolse the vessels and the red pulpy substance of the spleen. 



Fig. 620. SECTION OF HARDENED 

 SPLEEN-SUBSTANCE (from Kol- 

 liker after a preparation by 

 Billroth). 3*8 



The spleen had been hardened 

 in chromic acid and alcohol, a, 

 Malpighian bodies, one of them 

 having an artery dividing into 

 three twigs within, the other with 

 two arteries cut through ; 6, tra- 

 beculse ; c, artery ; in the re- 

 maining paits the clear spaces are 

 the capillary veins of Billroth, 

 the darker ones are the smallest 

 trabeculse of the spleen-substance. 



These fibrous structures are 



all composed of interlaced 



bundles of areolar tissue mixed with a large amount of fine elastic tissue. 



In addition to these elements, in the spleen of the pig, the dog, and the 



