THE BEGINNINGS OF LIFE. 569 



be conceded to the representatives of those vast multi- 

 tudes of infusorial and cryptogamic forms which col- 

 lectively constitute an ever-changing vital plexus, from 

 the various portions of which well-marked animals and 

 plants are constantly arising. Biological individuals, 

 in fact, exist which multiply prodigiously by agamic 

 processes long before a sexual mode of reproduction 

 begins to manifest itself, and therefore long before 

 'true generative acts' are performed, and before 

 c species' begin to exist. 



So that instead of considering the total product of 

 any one fecundated germ as a single individual (even 

 when it comprises what others would call hundreds 

 of individuals), an alteration in our conception of the 

 word 'species' which is now actually necessitated 

 suffices to clear away all the old difficulties. We 

 may quite easily recognize that, just as individuals 

 are either simple, or complex and aggregated, so 

 'species' may be represented either by definitely re- 

 curring series of different individuals, derived one from 

 another by agamic processes though the last of the 

 series develops rudimentary sexual organs in which 

 fertilized germs are produced, constituting the first 

 terms of the new series ; or else by single (hermaphro- 

 dite) or by double (male and female) recurring indi- 

 viduals, each of the representatives of which undergoes 

 a more or less metamorphic process of development. 



The views which we have hitherto announced also 



