"WASTE AND REPAIR. 177 



nervous discharges from distant organs ; it is clear that spe- 

 cial waste and general waste are too much entangled to 

 admit of a definite relation being established between special 

 waste and special activity. We may fairly say, however, 

 that this relation is quite as manifest as we can reasonably 

 anticipate. 



§ 64. Deductive interpretation of the phenomena of Re- 

 pair, is by no means so easy. The tendency displayed by an 

 animal organism, as well as by each of its organs, to return 

 to a state of integrity by the assimilation of new matter, 

 when it has undergone the waste consequent on activity, is a 

 tendency which is riot manifestly deducible from first princi- 

 ples ; though it appears to be in harmony with them. If 

 in the blood there existed ready-formed units exactly like in 

 kind to those of which each organ consists, the sorting of these 

 units, ending in the union of each kind with already existing 

 groups of the same kind, would be merely a good example of 

 Differentiation and Integration [First Principles, § 123). It 

 would be analogous to the process by which, from a mixed 

 solution of salts, there are deposited segregated masses of 

 these salts, in the shape of different crystals. But as already 

 said (§ 54), though the selective assimilation by which the 

 repair of organs is effected, no doubt results in part from an 

 action of this kind, which is consequent on the persistence of 

 force (First Principles, § 129), the facts cannot be thus wholly 

 accounted for; since organs are in part made up of units 

 that do not exist as such in the circulating fluids. The pro- 

 cess becomes comprehensible however, if it be shown that, as 

 suggested in § 54, groups of compound units have a certain 

 power of moulding adjacent fit materials into units of their 

 own form. Let us see whether there is not reason to think 

 such a power exists. 



" The poison of small-pox or of scarlatina," remarks Mr 

 Paget, " being once added to the blood, presently affects the 

 composition of the whole : the disease pursues its course, 



