26 Th. Lewis, 



the case when the sinuses are wide. Germ centres are plentiful and 

 a good many phagocytes are scattered throughout the sections. In 

 the horse, the sinuses are often broken up by strands of lymphoid 

 tissue; the germ centres are very frequently seen in the cortical 

 portion of the lymphoid tissue. Signs of phagocytosis are occasionally 

 observed. In the pig, the chief feature is the strength of the trabe- 

 culae, which to a large extent subdivide the organ. In these glands 

 I have not observed phagocytosis proceeding, but occasionally small 

 massés of pigment occur in the sections: destruction of erythrocytes 

 probably occurs to a slight extent. 



Carnivora. The glands all have a very characteristic appearance 

 (pi. I. fig. 3). There is never a complete peripheral sinus present; 

 blood spaces are only found in certain restricted areas beneath the 

 capsule. There is usually a large sinus in the centre of the gland, 

 which communicates with the peripheral sinuses by numerous small 

 interlacing minor sinuses; these last mentioned are smaller than any 

 met with in glands of the Ungulata or Primates and seem to be 

 characteristic of hœmal lymphatic glands. They contain hath Mood 

 and lymph in abundance, and probably have direct communication 

 with both blood and lymph streams. It is of course quite possible 

 that both blood and lymph sinuses are separately present, with but a 

 thin partition between them, and it is within the bounds of possibility 

 that erroneous conclusions may be sometimes drawn from injection ex- 

 periments, through the breaking down of such a partition. I am more 

 inclined to the view that one system of sinuses exists which contains 

 blood and lymph, since I can observe no histological differences between 

 the details of different sinuses; also injection of the sinuses by the 

 blood or lymphatic vessels shows that they are both connected with 

 one and the same system of sinuses. 



There exists in these glands therefore admixture of blood and 

 lymph streams. Large efferent vessels may be traced from these 

 glands to the thoracic duct, and it might be expected that blood 

 would be found in these. ^) 



^) In the case of a dog examined, an efferent lymph vessel, passing to the 

 thoracic duct, was observed to contain a considerable amount of blood, this has 



