THE RED PARTICLES. 285 



SECT. 107. The lachrymal gland secretes the tears; the 

 salivary glands the saliva; the kidneys, urine; the testicles, 

 semen, &c. &c., without the intervention of any auxiliary gland. 

 If then a fluid so elaborated, and so different from anything 

 we find in the blood, as semen is, a fluid which has an office 

 of no less dignity than to perpetuate the whole race of animals, 

 can be formed from the blood by the vessels of the testis, with- 

 out any preparatory change being produced on it, may we not 

 reasonably conclude that the liver is capable of secreting bile 

 from the blood without any antecedent change being made on 

 it by the spleen? For to say that the blood must be pre- 

 pared by the spleen, before bile can be secreted from it by the 

 liver, is to deny that the liver, which is given to form bile, can 

 do the office which nature has intended it to perform. 



SECT. 108. But if we allow the spleen to make the red part 

 of the blood, we can readily account for the reason why the 

 spleen may be cut out of an animal, and yet the animal survive, 

 and suffer but little inconvenience, for though the office of the 

 spleen is to form the red particles of the blood, yet it is not 

 the only organ in the body capable of doing that office ; for we 

 have already proved (sections 85 and 88) that the lymphatic 

 vessels do also form the vesicular portion ; the spleen, therefore, 

 is not the only organ capable of doing it. But nature has 

 given the spleen as an auxiliary to the lymphatic system, in 

 order to the more commodiously, expeditionary, and completely 

 forming the red part of the blood. 



SECT. 109. If, then, the spleen be cut out, or its office ob- 

 structed by disease, nature has a. resource, in exciting the 

 lymphatic vessels to form a larger quantity of red particles than 

 they had ordinarily been accustomed to do, and these in pro- 

 portion to the exigencies of the habit ; but here nature does 

 not assign a new office to the lymphatic vessels, but only excites 

 them to exert, in a higher degree, a power of which they were 

 before possessed, and this notion is conformable to what we ob- 

 serve in other circumstances of the animal economy ; as when an 

 animal is fat and well nourished, the stomach is much longer 

 in performing its office than it is when emaciated by long 

 fasting, and its life is in danger from want of nourishment, or 

 than it is when the body is wasting by disease, witness the 

 surprising quantities of food the stomach will digest in a short 



