334 peyer's and solitary glands. [sect. 155. 



the contents of the follicles when perfectly fresh and carefully 

 extracted. 



But little is accurately known about the lymphatic vessels of the 

 Peyerian glands. This much is established, that the number of 

 the chyle-vessels coming from the Peyerian patches during the 

 period of digestion is greater than at other parts of the intestine, 

 although the villi found upon them are less developed and more 

 scanty ; but it is entirely unknown how the chyle-vessels are 

 arranged in the interior. It appears probable, that they form 

 networks around the individual follicles — at least, we see from the 

 outside that they surround the follicles in a circular manner ; on the 

 other hand, they do not enter into the follicles, at least on this 

 surface, which entrance would be readily recognised by the 

 milk-white colour of the filled vessels. For this reason, if, as 

 Briicke has recently assumed, a direct communication of the 

 follicles with lymphatic vessels exists, it can take place only by 

 the follicles becoming connected with such vessels upon the surface 

 opposite to the cavity of the intestine. 



The solitary glands (glandules solitaries) agree so completely with 

 the individual elements of the Peyerian patches in size, contents, 

 and structure, and in respect of the vessels in their interior, which 

 I also observed even in man, that a separation of them is by no 

 means justifiable; especially too as all possible variations are 

 found in the number of the follicles and since, at least in animals, 

 there occur Peyerian patches with 2, 3 to 5 follicles. In man, 

 the number of the solitary glands, as all authors correctly state, 

 is extremely various ; sometimes we do not succeed in finding a 

 single one, sometimes the intestine is quite overstrewn with them, 

 as far as the border of the ileo-colic valve, or, finally, they are 

 found in the ileum and jejunum in moderate number. Their com- 

 plete absence may, perhaps, be regarded as an abnormal condition, 

 since, in newly-born infants and in the dead bodies of healthy 

 individuals, they are constantly present, and, indeed, more nume- 

 rously in the jejunum than in the ileum ; on the other hand, the 

 millet-seed-like vesicles, which, in catarrh of the alimentary tract, arc 

 often found in immense numbers in the small intestine and 

 stomach, may have either partially or completely a pathological 

 signification, since, in other organs also (as in the liver, according 

 to Virchow), the occurrence of similar follicles has been demon- 

 strated. The solitary follicles are embedded in the same way as the 

 elements of the patches, only they occur also upon the mesenterial 



