STERILITY OP HYBRIDS. 427 



recurrence of alternate degeneration and reintegration, 

 is a general characteristic of life ; but it is absurd to 

 pronounce it Life itself. It is more in keeping with 

 the phenomena, to term the coordination of actions, 

 Life. This Herbert Spencer has done; but he has 

 made an egregious mistake, when he fancies, that the 

 coordination, peculiar to any species, is susceptible of 

 any normal modification. 



As before remarked, there is no necessity more im- 

 peratively felt, than that of a test by reference to which, 

 the precise nature and bounds of the several species, 

 maybe susceptible of ascertainment; and, as the absence 

 of all explanation, both qualitative and quantitative, of 

 the varied phenomena of sterility and of fertility, has 

 heretofore lain in the way of attaining such a test, the 

 importance of the solution herein given of such varied 

 phenomena, cannot well be over-estimated. The hy- 

 brid is the sole possible element of confusion, in the 

 practical classification of species. Such organism, 

 whilst in theory affording no difficulty, may be often, 

 to the naturalist, a temporary source of confusion. 

 But, its sterility will preclude the possibility of its con- 

 fusing specific distinctions. Although ; when an indi- 

 vidual, of one species, with some of its characters re- 

 duced or suppressed, crosses with an individual of 

 another species, which has characters so like those 

 which the former lacks, that they may serve to repair, 

 in a measure, the defect in the coordination of the for- 

 mer ; gain in constitutional vigor results to the hybrid 

 offspring of such a cross ; the hybrid will, however, be 

 sterile, and the line of descent from either parent-form, 



