1 66 THE BEGINNINGS OF LIFE. 



' All forms of matter appear to have a tendency and 

 a capability to become organized, as all organic forms 

 tend to higher stages of development, and chemical 

 analysis shows the highest as well as the lowest forms 

 of organic beings to consist of a complicated aggregate 

 of mineral gases and liquids and solids. These organ- 

 ized aggregates once formed from their elem.ents, all 

 possess alike the means of transmitting their forms 

 by generation, which is effected by the separation of a 

 portion of their substance, when their own development 

 is completed. -^ ^ -^ 



^Although no animal can exactly produce its like, 

 the progeny are so nearly such that, for all the pur- 

 poses of science, we regard their forms as identical 

 with those of the parent, and out of an indefinite 

 series of such generations, and of individuals as nearly 

 resembling them, we frame our organic species, and 

 ascribe them to nature. ■5«- -^ ^ 



*The organs of nutrition and relation which we 

 have been hitherto considering, enable the individuals 

 of species for a limited time to live, to grow, and to 

 feel ; but while myriads of individuals appear and dis- 

 appear, like passing shadows, in rapid succession, the 

 species, or the typical forms of groups of animals, are 

 still prolonged on the earth. The species, however, 

 like the individuals which compose them, have also 

 their limits of duration. 



'The life of animals exhibits a constant series of 

 changes, which occupy so short a period, that we can 



