136 PHYSIOLOGY OF ORGANIC LIFE. 



which they act, are, in their nature, totally 

 different. While the former convey to the 

 blood the nutritious matter which the stomach 

 had assimilated; the latter, on the contrary, 

 are designed to remove and carry away those 

 pprts of the system which are worn out, and 

 which exisj; in a perishing and dying state ; 

 the former may be compared to cooks, who 

 constantly afford to the blood a supply, the 

 other to scavengers, who take away the dilapi- 

 dated parts of the system. 



It is in obedience to the diversity in the end 

 to which each system is subservient, that there 

 exists a diversity of power between them at 

 (different periods of life ; i infancy and youth, 

 while the system is in a state of progression 

 jin4 growth, the lac teals are large, and the 

 lymphatics comparatively small. At the middle 

 periods of life, when the system has attained 

 the acme of perfection, both systems are, as it 

 were, balanced ; in old age, on the contrary, 

 when emaciation and decrease take place, the 

 balance between them is altogether overturned, 

 aiicl both scales are put into one ; the lacteals 

 become weaker and smaller, while the lympha- 

 tics increase in magnitude and strength. In- 

 cJ of contemplating the action of these ves- 

 , with relation to the separate functions 

 which they are designed to perform, both are 

 generally confounded together; while the fpiv 



