186 Proceedings of the Royal Society of Edinburgh. [Sess. 
Sofer (34), too, distinctly states that external influences do not affect 
races, whilst Doncaster (35) stresses heredity rather than environment. 
Here, then, is nothing to account for the excessive range of variation of 
the Australian as compared with the Tasmanian, and we are thrown back 
on the hypothesis already furnished — namely, hybridity, and the explana- 
tion of same as given by Ewart. 
From a study of the question in all its phases we are, therefore, forced 
to the conclusion that the Australian is a hybrid. 
One other interesting fact results from our study of the hybridity 
of the Australian aboriginal as deduced from his range of variation, and 
that is that the result of the cross has not benefited the race from the 
evolutionary standpoint. The modern-day Australian aboriginal stands 
rather nearer the anthropoid ape, or the common ancestor, than did the 
Tasmanian. Isolated individuals of the Australian race have, on the 
other hand, surpassed the Tasmanian. These facts are evidenced in the 
present work by the application of Cross’s formula to all the evolutionary 
objects under comparison and by the study of maximum and minimum 
ranges of variation for Australian and Tasmanian. 
Results. 
In conclusion we may say that, as a result of our prolonged study 
of Australian and Tasmanian craniology — a study which has now occupied 
us over five years and is still in progress, — we are led to the following 
conclusions : — 
1. The Australians and Tasmanians are the descendants of a common 
late Pliocene or early Quaternary stock which, for want of a better term, 
may be called with Sergi, Homo tasmanianus. H. tasmanianus had a 
wide range of distribution within the the islands of the Pacific Ocean 
(Sergi). 
2. The Tasmanian aboriginal was the almost unchanged offspring of 
this type, but evolved on his own lines and in his own way. 
3. The Australian aboriginal is the result of a cross between the 
primitive Homo tasmanianus and some other unknown race — Polynesian, 
according to Sergi; Dra vidian, according to Mathew — and is, therefore, 
a hybrid. From the evolutionary standpoint the result of the cross, 
whilst it has not been favourable to the race as a whole, has benefited 
individual members of it. Once evolved, the Australian has, like the 
Tasmanian, progressed on his own lines and in his own way. 
4. Both Australian and Tasmanian have attained, morphologically, 
to a higher stage in the evolutionary scale than is usually supposed. 
