ON THE LYMPHATIC SYSTEM. 159 



spaces (see below), while the membraua propria of the alveoli 

 forms the other. 



As mentioned above, ordinary small homogeneous looking 

 lymph-corpuscles and plasma-cells occur in the inter- and intra- 

 alveolar tissue. The following points are worth stating as 

 regards their occurrence : 



1. In the parotid: (a) in the dog, the inter- and intra- 

 lobular tissue contains few plasma-cells ; ordinary lymph-cor- 

 puscles occur chiefly in the immediate neighbourhood of the 

 intralobular ducts, in some glands more numerously than in 

 others ; (3) in the ape, the ordinary lymph-corpuscles are more 

 numerously met with than in the dog ; they occur especially in 

 the interlobular tissue ; in some places they are infiltrating the 

 tissue around the blood-vessels to such an extent as to form 

 adenoid sheaths around them ; within the lobules they are also 

 present in considerable numbers ; (c) in the rabbit there is this 

 conspicuous feature, that small and large fat-cells are present in 

 the intra- and interlobular tissue, both isolated and in small 

 groups J (d) in the guinea-pig a few ordinary lymph-corpuscles 

 are seen in the interlobular connective tissue. 



2. In the submaxillary gland : {a) in the dog, we find both 

 plasma-cells and ordinary lymph-corpuscles in the inter- and 

 intralobular tissue; (b) in the human submaxillary gland, the 

 ordinary lymph-corpuscles are of common occurrence ; a few fat- 

 cells are seen in the intralobular tissue in some glands ; (c) in 

 the ape, a few ordinary lymph-corpuscles are present in the 

 interlobular tissue ; (d) in the rabbit, considerable numbers of 

 isolated ordinary lymph-corpuscles occur in some places both in 

 the inter- and intralobular tissue ; {e) in the guinea-pig the 

 connective tissue surrounding the larger ducts is sometimes 

 infiltrated with ordinary lymph-corpuscles. 



3. In the sublingual gland : (a) in the dog a great many 

 lymph-corpuscles are present in the interalveolar tissue, and also 

 within the lobules we find the alveoli separated by streaks and 

 rows of lymph-corpuscles. These are of various sizes, each 

 with a spherical nucleus, staining readily in logwood ; their cell- 

 substance appears transparent, and owing to their close position 

 the outlines of the cells are more or less angular. But where 

 they are not closely placed side by side they appear, in shape, 

 identical with the ordinary lymph-cells. A few plasma-cells are 

 also to be met with in the intralobular tissue. Lavdowsky (1. c, 

 p. 318) considers the above lymph-corpuscles identical with the 

 interstitial parenchymatous cells of the testis ("VValdeyer, Mihal- 

 kovich), which he assumes to be plasma-cells. In neither of 

 these views can I agree with him, for in the first place the 

 interstitial cells of the testis are epithelial cells, remnants of the 



