224 LECTURE IX. 



occurrence can be just as simply explained according to 

 our theory of haematopoiesis, as it previously seemed 

 explicable only according to that of pyaemia. Irritation 

 of the lymphatic glands explains without any difficulty 

 the increase in the colourless, pus-like cells in the blood, 

 and that too in all cases not only in those where 

 pyaemia was expected to be found, but also in those 

 where it was not expected, but where the blood, not- 

 withstanding, exhibited the same quantity of colourless 

 corpuscles as in genuine pyaemia answering to our 

 clinical notions of the disease 



Thus it has been shown that every meal produces a 

 certain state of irritation in the meseiiteric glands, inas- 

 much as the constituents of the chyle which are conveyed 

 to these bodies, act as a physiological stimulus to them. 

 The milk which we drink, the fatty matters in our soups, 

 the various kinds of fat distributed in a state of minute 

 division throughout the more solid articles of our food, 

 find their way in the form of extremely minute globules 

 into the lacteals and diffuse themselves there just like the 

 cinnabar in the glands ; but the smallest of the fatty 

 molecules after a time force their way through the gland. 

 For such minute bodies therefore there still exists a real 

 permeability in the channels of the gland, but even they 

 are for a time retained, and it always takes a long time 

 before the mesenteric glands after a meal again become 

 entirely free from fat, and the propulsion of this sub- 

 stance through them is manifestly effected by a propor- 

 tionately strong pressure. At the same time we observe 

 an enlargement of the gland, and likewise after every 

 meal an increase in the number of colourless corpuscles 

 in the blood a physiological leucocytosis, but no pyaemia. 



In proportion as pregnancy advances, as the lymphatic 

 vessels in the uterus dilate, and the interchange of mate- 

 rial in the organ increases with the development of the 



