The Structure and Functions of the hœmolymph Glands and Spleen. 5 



Clarksoiis paper [5], wliicli appeared in 1891, gave a further 

 detailed description. The animals he examined were the sheep, 

 horse, and pig, in which the glands were found, while in the camel, 

 leopard, dog, cat, rabbit and rat he was unsuccessful in his search 

 for them. He seems to have sought in the renal region onlj^, though 

 he suggested that possibl^^ they might be discovered in other regions 

 in the case of the sheep. It is indeed surprising he should have 

 overlooked the very numerous and conspicuous glands already described 

 by Eobertson in this animal in the subvertebral region, and that those 

 present in the dog, cat and rat should have escaped his notice. His 

 examination of the camel and leopard probably gave negative results, 

 because he restricted his search to a limited region. He laid stress 

 on the presence of certain large cells, since called phagocytes, which 

 he considered, from the examination of cover glass preparations, con- 

 tained in many cases red blood corpuscles in the process of formation. 

 His conclusion that hœmolymph glands have the important function 

 of elaborating erythrocytes, was apparently based upon the appearance 

 of a single phagocyte in a preparation of this character, which in his 

 opinion was extruding a blood corpuscle; and also from the fact that 

 globules, resembling erythrocytes of the sinus, were to be seen within 

 the giant cells. He noted the presence of golden yellow pigment in 

 his sections, but did not grasp its significance; his article concluded 

 with a comparison of the general structure and arrangement of the 

 lymphoid tissue of haemal glands with that of the spleen. 



The contribution of Vincent and Harrison [16] furnished a general 

 and detailed account of hgemolymph glands in the ox, sheep, rat, dog 

 and fowl, with a note on those in man. They were the first of the 

 English writers to advance the view, that these glands are connected 

 with blood destruction, considering the process to be similar to that 

 described by Kölliker [.9b] in the spleen. They described also the 

 general appearance of the compound glands in the dog, now known 

 as "hœmal lymphati&^ glands; and Vincent [l?})] subsequently noted 

 similar glands in the cat. Vincent and Harrison were further of the 

 opinion that these glands, namely ""hœmolymph glands^'' are modified 

 ymphatic glands and j^robably developed from them; also that they 



