DISTRIBUTION OF MANKIND 19 



tube ; the highly developed muscular system, and the perfection 

 of the urinary and genital organs. In all these respects man 

 corresponds, broadly speaking, not only to all the other 

 mammals, but to birds, reptiles, amphibia and fishes ; hence all 

 mammals, birds, reptiles, amphibia and fishes must be descended 

 from a common prototype. 1 Now as the fishes occupy the 

 lowest position among the vertebrates, Darwin is justified in 

 concluding that all vertebrates are descended from a fish- 

 like prototype. As lowest of the fishes once ranked the 

 Amphioxus lanceolatus with its small, symmetrical, lancet- 

 shaped body, without brain or heart, and, strictly speaking, 

 without a head ; since it possesses in place of a vertebral 

 column merely a Chorda dorsalis, such as is found in the 

 Ascidians, Darwin 2 concludes that here we have most probably 

 the parent form of the vertebrates. Haeckel 3 carries his in- 

 vestigations of man's ancestry still farther back, extending them 

 to still lower invertebrate animals. Thus he takes the Gastraea 

 as ancestor of all the Metazoa, because it represents the gastru- 

 lar stage of all Metazoa, the members of the Volvox genus as 

 representing the blastula stage in the development of the Meta- 

 zoa, and lastly the Protozoa corresponding to the single-celled 

 egg. As connecting link between the lowest Metazoa and the 

 Ascidians on the one hand, and the Amphioxus on the other, 

 Haeckel selects the Frontonia, a class of the humblest chordate 

 animals, from which are descended both molluscs and mammals. 

 The Frontonia form a branch of the invertebrates, which in 

 their turn are probably descended from the Rotatoria, or wheel 

 animalcules. 



Distribution of Mankind. 



For many centuries we have unhesitatingly accepted the 

 Mosaic classification of man as descendants of Shem, Ham and 

 Japhet, the three sons of Noah. The tribes described by Pliny 

 in his Natural History and mentioned by Sebastian Munster 

 in his Cosmography (sixteenth century), were regarded as 

 particularly abnormal : the Cynocephali, the Cyclops, the 

 Megapods and sundry other monsters haunted the mind of 



1 Darwin, vol. v., p. 206. 2 Darwin, vol. v., p. 208. 



3 Haeckel, Lecture, etc., p. 27. 



