200 LYMPHATICS AN!) NERVES OF THE SPLEEN. 



passes freely into spaces of the adenoid tissue of the pulp " in the same 

 way as the water of a river finds its way amongst the pebbles of its 

 bed," these "intermediary passages" being bounded directly by the 

 cells and fibres of the net-work of the pulp. From these passages the 

 venous radicles arise. At first, their walls are imperfect and cribri- 

 form, and they often present peculiar transverse markings due to the 

 circular disposition of the elastic fibres of the reticulum. The small 

 veins have at first a different course from the arteries. They anasto- 

 mose freely, but they soon become ensheathed, and accompany the 

 arteries in their course.] 



Elements of the Pulp. The morphological elements are very 

 various (1.) Lymph corpuscles of various sizes, sometimes partly 

 swollen, and at other times with granular contents. (2.) Red blood- 

 corpuscles. (3.) Transition forms between 1 and 2 [although this is 

 denied by some observers ( 7 C)]. (4.) Cells containing red blood- 

 corpuscles and pigment granules. [These cells exhibit amoeboid move- 

 ments.] (Compare 8.) 



[The Lymphatics undoubtedly arise within the spleen. The lym- 

 phatics which leave the spleen are not numerous (Kolliker). There 

 are two systems a superficial, capsular, and trabecular system ; and a 

 peri-vascular set. The superficial lymphatics in the capsule are rather 

 more numerous. Some of them seem to communicate with the 

 lymphatics within the organ (Tomsa, Kolliker). In the horse's spleen, 

 they communicate with the lymphatics in the trabeculae, and with the 

 peri-vascular lymphatics. The exact mode of origin of the peri-vascular 

 system is unknown, but in part at least it begins in the spaces of 

 the adenoid tissue of the Malpighian corpuscles and peri-vascular 

 adenoid tissue, and runs along the arteries towards the hilus. There 

 seem to be no afferent lymphatics in the spleen such as exist in a 

 lymphatic gland.] 



The Nerves of the spleen are composed for the most part of non- 

 medullated nerve-fibres, and run along with the artery. Their exact 

 mode of termination is unknown, but they probably go to the blood- 

 vessels and to the muscular tissue in the capsule and trabecula?. [They 

 are well seen in the spleen of the ox, and in their course very small 

 ganglia placed wide apart, have been found by Remak and W. Stirling.] 



Chemical Composition. Several of the more highly oxidised stages of albu- 

 minous bodies exist in the spleen. Besides the ordinary constituents of the blood, 

 there exist : leucin, tyrosin, xanthin, hypoxanthin ; also lactic, butyric acetic, 

 formic, succinic, and uric acids, and perhaps glycero-phosphoric acid (Salkowski) ; 

 Cholesterin, a glutin-like body, inosite, a pigment containing iron, and even free 

 iron oxide (Nasse). The ash is rich in phosphoric acid and iron poor in chlorine 

 compounds. The splenic juice is alkaline in reaction ; the specific gravity of the 



