The Structure and Functions of the h?emolymph Glands and Spleen. 17 



In Anguilla anguilla, Vincent^) states that he has found one or 

 two tj^pical haemolymph giands, embedded in the abdominal fat, though 

 he has not given details of the minute structure. 



IV. Distribution in Vertebrata. 



The account, which has just been given of the general anatomj^ 

 of hîçmol3anph glands, deals only with the distribution of the glands 

 in each of the individuals examined. When a comparison is made of 

 the different examples of the several groups certain interesting points 

 may be observed. 



The mammals examined have been nembers of five orders. Pri- 

 mates, Ungulata, Carnivora, Rodentia, Insectivora. In the first two of 

 these, typical hœmal glands have always been found; and they appear 

 to be restricted to these two orders. Thus they have so far been noticed 

 in man, monkey, sheep, ox, horse, goat and pig, and in no other ani- 

 mals. AVe may therefore say, that as far as is known, typical hœmal 

 glands are characteristic of the Primates and Ungidates. On the 

 other hand in the group Carnivora no hœmal glands, hid only hœmal 

 lymp)hatic glands are found, and these seem to be constantly present 

 in ^'renal" and "splenic" groups. Of the Carnivora the following 

 species have been examined, and in all, the distribution was found to 

 be similar: — dog, cat, ferret, stoat and weasel. In the group Ro- 

 dentia, there exists a type of gland which may be called "hœmal" 

 but which differs in several respects from the h£emal glands of Un- 

 gulata. The species examined include the rabbit, several varieties of 

 rats and mice, and the guinea pig, squirrel, water vole, and shrew. 

 In the Guinea Pig the glands appear to be intermediate forms, which 

 can hardly be definitely called either "haemal" or "hsemal lymphatic". 



Several observers have failed to find the glands in certain mam- 

 mals; Clarkson-) could discover none in the camel and leopard, while 

 Vincent and Harrison-^) failed to find them in the hedgehog.*) But the 

 same observers failed to find the glands present in a number of ani- 

 mals examined, in which they undoubtedly exist. I believe, that 



^) Loc. cit. -) Loc. cit. ^) Loc. cit. 



') As already observed, they have since been seen in the hedgehog. 

 Internationale Monatsschrift für Anat. u. Phys. XX. 2 



