568 THE BEGINNINGS OF LIFE. 



From what has been hitherto said^ it would appear that 

 nothing comparable to those assemblages which have pre- 

 viously been understood to constitute a ^ species ' can be 

 considered to exist till sexual generation begins to mani- 

 fest itself and tends to recur. Such forms, however, have 

 been, and are being, gradually evolved in ascending series 

 from an enormous plexus of ephemeromorphs, which is 

 itself being constantly reinforced from the inorganic 

 world. This plexus is composed of untold legions of 

 organisms — partly animal and partly vegetal, and of an 

 inexpressibly varied size, shape and hue — many of which 

 are possessed of an enormous power of independent 

 self- multiplication, and of adapting themselves to 

 changed conditions by taking on entirely new forms. 

 We have now seen, moreover, that many of the earliest 

 ^species' which appear are represented by a definite 

 succession of varied forms — such as we meet with in 

 the cases of so-called ^ alternate generation.^ 



So that (referring to the question which we have 

 already in part discussed i), as distinct ^species' are no 

 longer found, in all cases, to consist of only one set of 

 distinct individuals, and as no such assemblages of 

 similarly recurring forms begin to exist till we arrive 

 at plants and animals which have attained some degree 

 of complexity, it is our notion of the meaning of this 

 word ^ species^ which ought to undergo change, rather 

 than our notion of the meaning of the word '^indi- 

 vidual.' Individuality in every sense of the word must 

 1 See pp. 553-557. 



