THE ORIGIN OF MAN 105 



need to recapitulate the biologist's finding that the highest 

 members of the group below do not in general become the 

 ancestors of the lowest members of the groups above. I need 

 only instance the case of the much-debated question of the 

 origin of the vertebrates. Did their lower members arise 

 from the highest of the invertebrates, which stand immediately 

 below them in the scale of life ? To my mind the work of the 

 late Richard Assheton makes it perfectly clear that there is 

 no meeting-point of vertebrate and invertebrate nearer than 

 the Coelentera|ta. It was not that the highest invertebrates 

 became the progenitors of the vertebrates, but that the two 

 stocks arose in common from so simple a form of life as the 

 hydra, and branched off, each along the line to which its 

 definite structural bias had committed it. The middle portion 

 of the scale of life has afforded an object of special study for 

 the zoologist and the palaeontologist. Here, again, all the 

 evidence gained from patient researches upon the phylogeny 

 of the main groups of the vertebrates has altogether discredited 

 any belief in " end on " evolution. Multiserial evolution, by 

 which many stocks arise and diverge along their own line, is 

 the order of development, rather than the transition of one 

 group into its next higher neighbour. To take a very obvious 

 example, it is not the highest reptile, not the most perfected 

 expression of reptilian development, that leads the way to 

 the lowest member of the group above, but the lowest reptile, 

 the least developed and differentiated member of its phylum, 

 which makes a bond with other phyla. We have a series of 

 evolving lines, and no march of progress to perfection along a 

 single line. 



If, then, such are the findings of those who have patiently 

 investigated the lower end, and the middle, of the scale of 

 being, what conclusions have been arrived at by those who 

 have investigated its immediate culmination ia the highest 

 order of the mammals ? 



So far as influencing opinion is concerned, it is safe to say 

 that the examination of the highest rungs of the scale remained 

 in the hands of Huxley and Haeckel in that stormy epoch of 

 the immediate post-Darwinian period. Of their findings there 



