418 



MANUAL OF HISTOLOGY. 



exist in the glands in question, and that the views entertained to the ' 

 opposite effect are incorrect, as those of Teichmann* for instance. 



On the other hand, that older and so widely held view to which we our- 

 selves subscribed for many years can no longer 

 be supported in its integrity, namely, that only 

 lacunar circulation takes place within the 

 lymph, nodes. The lymphatic canals, namely, 

 traversing the capsule are, as we may easily 

 convince ourselves, lined with peculiar flat 

 epithelium-like cells (fig. 410), already dealt 

 with in considering the vascular system 

 ( 208). The investing spaces are likewise 

 lined in the same manner, not only on the 

 surfaces of the septa and the retinacula con- 

 nected with them, but those of the follicles 

 themselves (His). It is still a matter of uncer- 

 Fig . 410. tainty whether the lymph passages of the 



medulla possess a similar lining or no. This 



matter calls, at all events, for more accurate investigation ; for we find 

 not alone after artificial injection, but also from the stream of lymph pass- 

 ing through that small granules of colouring matters or fats penetrate 

 from the periphery towards the centre of the follicles, and also into the 

 lymph tubes. They are also seen in the cellular network passing across 

 the interstices of the medullary portion of the gland. We know, farther, 

 that the lymph of the afferent vessels is not unfrequently poorer in cells 

 than that which leaves the organ. From this fact we may infer that 

 from the substance of the gland lymph corpuscles are yielded to the 

 passing fluid. The lively change of shape of the cells of the latter, and 

 consequent power of change of locality ( 40), as well as the trellis-like 

 surface of both follicle and lymph tube the fact, finally, which has been 

 already considered in a previous section, that cellular networks containing 

 lymph corpuscles are observed in the passages of the medulla, all these 

 point to the probability of such an addition being here made to the fluid. 

 Our knowledge of the nervous supply of the lymph glands is at present 

 extremely scanty. Some fine nervous twigs have been observed by Koel- 

 Wcer, in the larger nodes of the human body, to pass in with the arteries 

 into the medullary portion ; beside which Remains pale nerve fibres have 

 also been observed in the glands of the ox. 



REMARKS. 1. No doubt can any longer prevail as to the perviousness of the 

 lymph glands to small solid granules. And although, after tatooing, molecules of 

 pigmentary matter are laid down in these organs, the fact can be explained in a 

 manner quite reconcilable to this view. Every one who has ever injected lymph nodes 

 with any granular matter, and afterwards essayed to brush it out, knows very well 

 with what tenacity the granules cling to parts of the surface of the investing space. 

 That lymphoid cells possess the power of taking up molecules of pigmentary matter 

 into their bodies has already been remarked at p. 77. Why it is that Virchow still 

 doubts the possibility of the passage of pus cells, or even granules of cinnabar, through 

 lymph glands, is to me somewhat incomprehensible. 



226. 



It has been long supposed, and rightly so, from physiological experi- 

 ences, that a lively interchange of matter takes place in the lymph nodes 

 between the blood and the lymph. The same is taught us by the changes 

 produced in the glands in question in morbid states of the juices of the 



