The Structure and Functions of the hsmolymph Glands and Spleen. 3 



desirable to emploj^ this term for blood-lympli structures generally, 

 so that imder the heading will fall all such oi'gans as spleen, accessory 

 spleens, hïenial giands, hoemal lymphatic glands, and lymphatic glands. 



The statement has been made by Weidenreich [19 a] that the 

 spleen has no lymphatic supply; I am able to confirm him to this 

 extent, that no purely lymphatic sinuses have been found in this 

 organ. 1. To the spleen and to all other organs of the hsemolympli 

 series n-hich are without these lymphatic sinuses, the name ^'hcemal 

 fjland" mil be applied, to signify that the fluid spaces found within 

 them contain blood only. 2. Ordinary ^'lymphatic glands^'' are so cal- 

 led because their sinuses contain lymph only. 3. To intermediate 

 structures, such as the '^compound giands" found in the dog and cat, 

 which contain a mixture of hlood and lymph in their sinuses, the 

 term "hœmal lymphatic gland" will be applied. These three varieties 

 of giands will be referred to in the following article by the terms al- 

 ready mentioned^): but it may be well to point out at this stage that 

 the nomenclature must not be too rigorously applied, as all inter- 

 mediate forms are met with between the three types, in various animals: 

 thus a gland may contain sinuses in which is seen abundance of blood, 

 while the lymph is scanty; or there may be sinuses which contain a 

 considerable amount of lymph, while the blood is inconspicuous. 

 A complete series of organs thus exists, with the typical haemal gland 

 at one extremitj^, and the ordinary lymphatic gland at the other. 



In using the words blood, or lymph sinuses, I wish .to carefully 

 avoid reference to the minute bloodvessels or lymphatic ducts, which 

 may pervade the tissue of lymphatic or haemal gland respectively. 

 The terminology is entirely based upon the contents of the larger 

 spaces which may be more properly designated "sinuses". 



The present investigation- was suggested to me by Mr. Swale 

 Vincent, Lecturer in Histology at University College, Cardiff, and I 

 take this opportunity of thanking him for the generous advice he has 

 given me on many points. 



^) For the sake of convenience in the ensuing paragraphs I shall refer to 

 typical blood red glands as hœmal glands, without including the spleen under 

 this term. 



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