336 THE EVOLUTION THEORY 



multicellular organisms, such as they are now, would even have been 

 possible. If these organisms were to attain to such a high degree of 

 functional capacity and of structural complexity as they now exhibit, 

 they obviously could not also have been adapted at the same time to 

 an eternal persistence of life. 



This is in perfect harmony with our whole conception of the 

 impelling forces in the development of the organic world ; the ever- 

 increasing functional capacity of the structure arose from the advan- 

 tage which this afforded in the struggle for existence, in comparison 

 with which the apparent advantage of the endless life of the individual 

 was of no account whatever. 



I will not here follow out this idea. I have merely touched on it 

 in order to make clear that the death of individuals in all multi- 

 cellular organisms gives us no ground for thinking of the unlimited 

 life of the germ-cells as dependent on a special artifice of nature, such 

 as amphimixis is often supposed to be. Let us always remember that 

 there is parthenogenesis, and that there are unicellular germs (spores) 

 which are never fertilized, and that the reproduction of many species , 

 of animals and plants occurs in this way without the intervention of 

 amphimixis at all. 



Attempts have recently been made to prove that parthenogenesis 

 is a kind of self-fertilization, and these have been based on the 

 observations of Blochmann and Brauer, which showed that in the bee 

 and in the salt-water Crustacean, A rtemia talina, the reducing second 

 maturation division of the ovum-nucleus is not suppressed, but is 

 regularly accomplished, and that the two daughter-nuclei which result 

 from this division unite with each other subsequently. I have already 

 noted that these statements do not hold true, at least with regard 

 to the bee. In this case the second maturing division takes place 

 without any subsequent fusion of the two daughter-nuclei. According 

 to the observations of Dr. Petrunkewitsch, which I have already 

 mentioned, and for the exactness of which I can vouch, the second 

 maturation-spindle is unusually long, so that the two daughter-nuclei 

 are pushed very far apart (Fig. 79, Rsp 2), and only the inner of the 

 two nuclei (K4) becomes a segmentation nucleus, while the outer 

 undergoes a remarkable fate ; it unites with the inner nucleus which 

 results from the division of the first maturation cell (K 2), and from 

 this union the primitive genital cells of the animal appear to arise — 

 an observation the eventual theoretical importance of which can only 

 be estimated later. 



