FUNCTION. 155 



accumulation. In animals, the function of accumulation 

 comprehends those processes by which the materials contain- 

 ing latent force are taken in, digested, and separated from 

 other materials ; the function of transfer comprehends those 

 processes by which these materials, and such others as are 

 needful to liberate the forces they contain, are conveyed 

 throughout the organism ; and the function of expenditure 

 comprehends those processes by which the forces are liberated 

 from these materials, and transformed into properly co-ordin- 

 ated motions. Each of these three most general 

 divisions, includes several more special divisions. The accu- 

 mulation of force may be separated into alimentation and 

 aeration ; of which the first is again separable into the 

 various acts gone through between prehension of food and 

 the transformation of part of it into blood. By the transfer 

 of force is to be understood what we call circulation ; if the 

 meaning of circulation be extended to embrace the duties of 

 both the vascular system and the lymphatics. Under the 

 head of expenditure of force, come nervous actions and mus- 

 cular actions : though not absolutely co-extensive with ex- 

 penditure, these are almost so. Lastly, there are the 

 subsidiary functions which do not properly fall within any 

 of these general functions, but subserve them by removing 

 the obstacles to their performance : those, namely, of ex- 

 cretion and exhalation, whereby waste products are got 

 rid of. Again, disregarding their purposes and 

 considering them analytically, the general physiologist may 

 consider functions in their widest sense as the correlatives of 

 tissues — the actions of epidemic tissue, cartilaginous tissue, 

 elastic tissue, connective tissue, osseous tissue, muscular 

 tissue, nervous tissue, glandular tissue. Once more, 

 physiology in its concrete interpretations, recognizes special 

 functions as the ends of special organs — regards the teeth as 

 having the office of mastication ; the heart as an apparatus 

 to propel blood ; this gland as fitted to produce one requisite 



