552 



SPECIAL HISTOLOGY. 



it all communicate, contain the red pulp of the spleen and the Malpig- 

 hian corpuscles, and although no one exactly resembles another, yet all 

 as regards form and size, present a certain similarity. 



The older anatomists considered them to be regular cavities lined by a 

 membrane, like those of the corpora cavernosa penis, to which, indeed, 

 they are very similar in the arrangement of the limitary trabeculce, but 

 there is nothing of this kind, as may be best demonstrated in sections 

 of the spleen, in which pulp has been removed by washing. Such a 

 preparation is best fitted for the study of the relations and connections 

 of the trabeculce ; and it is readily seen, that although very various in 

 size, they do not ramify after the fashion of vessels, but unite quite 

 irregularly. Where 4, 5, or more of these unequally thick trabeculce 

 unite, a flattened cylindrical enlargement, like a nervous ganglion, 

 usually exists ; these are more frequent towards the external surface of 

 the organ than in its internal portions and at the hilus, where the large 

 vessels already afford a sufficient support to the parenchyma and an 

 intimate union of the trabeculce is less necessary. 



The structure of the trabeculce of the human spleen perfectly re- 

 sembles that of the fibrous coat ; they consist 

 of longitudinally fibrous connective tissue, with 

 intermingled fine elastic fibres. In animals, 

 on the other hand, smooth muscles exist, as I 

 showed in the year 1846, sometimes in all the 

 trabeculce (Pig, Dog, Cat), sometimes (Ox), 

 only in the smaller ones, with respect to whose 

 distribution further particulars will be found 

 in my " Mikroskopische Anatomic," II. 2, p. 

 256. In the trabeculce also, we find peculiar 

 spindle-shaped fibres, of 0-02-0-03 of a line 

 in length, and 0-002 of a line in breadth, with 

 undulated ends and prominent enlargements, 

 in which rounded nuclei are situated. They 

 are to be met with in great numbers in the 

 splenic pulp of Man (Fig. 227 A\ and I for- 

 merly, though as I now believe wrongly, took them to be smooth mus- 

 cles. What their nature is I cannot say, and I can only add that they 

 are also found coiled up in cell-like bodies* (Fig. 227 'B}. 



167. MalpigMan corpuscles, i^Q splenic corpuscles, Malpigliiancorpu- 



FiG. 227. Peculiar fibres from the pulp of the human spleen : A, the same free; B, one 

 inclosed in a cell; magnified 350 diameters. 



* [According to Mr. Wharton Jones (" British and Foreign Med. Chir. Review/' Jan., 

 1853), these cells, containing "peculiar fibres," are nothing but the ordinary nucleated fibres 

 of the pulp " circularly coiled, the coil being maintained by a tenacious intercellular substance 

 filling up the middle space." TRS ] 



