488i Mr. J. D. Dana on Species. 



powers, and the realization of the end of its being. We com- 

 prehend the type-idea only when we understand the cycle of 

 evolution through all its laws of progress, both as regards the 

 living structure under development within, and its successive 

 relations to the external world. 



2. Permanence of species. 



What now may w^e infer with regard to the permanence or 

 fixedness of species from a general survey of nature ? 



Let us turn again to the inorganic world. Do we there find 

 oxygen blending by indefinite shadings with hydrogen or with 

 any other element ? Is its combining number, its potential 

 equivalent, a varying number, — usually 8, but at times 8 and a 

 fraction, 9, and so on ? Far from this, the number is as fixed as 

 the universe. There are no indefinite blen dings of elements. 

 There are combinations by multiples or submultiples, but these 

 prove the dominance and fixedness of the combining numbers. 



But further than this, fixed numbers, definite in value and 

 defiant of all destroying powers, are well known to characterize 

 nature from its basement to its top-stone. We find them in 

 combinations by volume as well as weight ; that is, in all the 

 relations of chemical attraction ; in the mathematical forms of 

 crystals and the simple ratios in their modifications, — evidence 

 of a numerical basis to cohesive attraction ; in the laws of light, 

 heat, and sound. Indeed, the whole constitution of inorganic 

 nature, and of our minds with reference to nature, as Professor 

 Peirce has well illustrated, involves fixed numbers ; and the uni- 

 verse is not only based on mathematics, but on finite determinate 

 numbers in the very natures of all its elemental forces. Thus 

 the temple of nature is made, we may say, of hewn and measured 

 stones, so that, although reaching to the heavens, we may measure, 

 and thus use the finite to rise towards the infinite. 



This being true for inorganic nature, it is necessarily the law 

 for all nature ; for the ideas that pervade the universe are not 

 ideas of contrariety, but of unity and universality beneath and 

 through diversity. 



The units of the inorganic world are the weighed elements 

 and their definite compounds or their molecules. The units of 

 the organic are species, which exhibit themselves in their simplest 

 condition in the germ-cell state. The kingdoms of life in all 

 their magnificent proportions are made from these units. Were 

 these units capable of blending with one another indefinitely, 

 they would no longer be units, and species could not be recog- 

 nized. The system of life would be a maze of complexities; 

 and whatever its grandeur to a being that could comprehend the 

 infinite, it would be unintelligible chaos to man. The very beau- 

 ties that might charm the soul would tend to engender hopeless 



