CROSSING AND CLOSE-INTERBREEDING. 195 



obvious, theoretically ; but, in default of positive proof 

 thereof, it is all mere speculation. At the same time, 

 it will be admitted that, if such required proof is 

 adduced, the principle of one, normal type, to each 

 species, and the principle that all positive variations are 

 but the regain of lost or reduced characters, are demon- 

 stratively proven. 



Such proof is available. The phenomena of Cross- 

 ing, and of Close-Interbreeding, conclusively, aye, 

 demonstratively, show, that an organism is vitiated by 

 the reduction, suppression, or absence of any character 

 or characters of its species. They show, that- any 

 ratio, between the characters of which an individual is 

 composed, other than that ratio which subsists, when 

 all of the positive features of the species are fully 

 and proportionately developed, impairs the normal 

 coordination of the parts. They show, there can be 

 perfect coordination of parts in an individual, only 

 when all the . positive characters of its species are 

 present and fully developed. They show that, in each 

 species, all of the positive features, which it is possible 

 for such species to develop, are wonderfully united, 

 and have such delicate and intimate relations, that it is 

 impossible to vary the proportions of such parts, with- 

 out detriment to the organism, as a whole. They 

 show, that such reciprocal dependence of all the char- 

 acters, of a species, on each other, precludes the possi- 

 bility of any organism being modified in any part, 

 without entailing a breach of the laws of organization. 

 They show, that the laws, of the whole organism, fail 

 to operate fully, perfectly, or normally, when any of 



