i 9 z THE POPULAR SCIENCE MONTHLY. 



sion of a man-ape, it being understood that the skull we are describing 

 is not a natural, but an anomalous formation." ' 



It would be difficult to imagine, indeed, that mere reduction in 

 the size of the brain, through arrest of development, should produce 

 a series of characters so closely resembling the apes as is found to be 

 the case in so many widely-separated examples. Thus, in the Mau- 

 ritius microcephalic skull the capacity is only twenty-five cubic inches. 

 The jaws are extremely prognathous, the zygomatic arches stand out 

 wide and free, and the temporal ridges approach within one and a 

 quarter inch. If such examples should prove to be veritable cases 

 of reversion, then we have a parallel in the startling appearance of 

 the long-lost rudimentary toes of the horse, traces of which are only 

 seen in the hidden splint-bones. In the " Seventh Annual Report of 

 the Archaeological Museum," Prof. Wynian describes a microcephalic 

 skull from the ancient huacals of Peru. Its capacity is only thirty- 

 three cubic inches ; " the frontal bone is much slanted backward, has 

 a decided ridge corresponding to the frontal suture, and is slightly 

 concave on each side of it." 



Wyman states that the bones of the head are well formed, though, 

 from the diminutive size of the brain, idiocy must have existed. 



Associated with the remarkable collection of platycnemic tibia? 

 and perforated humeri discovered by Mr. Henry Gillman, we should 

 have expected some anomalous forms of crania, and in this expecta- 

 tion we are not disappointed. 



In company with two skulls which appear to be normal, Mr. Gill- 

 man discovered one of most remarkable proportions. Wyman con- 

 siders it a case of extreme individual variation, and not the result of 

 artificial deformity. The skull in question has only a capacity of 

 fifty-six cubic inches. The average capacity of Indian crania, accord- 

 ing to Morton's measurements, being eighty-four cubic inches, and 

 the minimum capacity being sixty-nine cubic inches, the skull of Gill- 

 man is therefore thirteen cubic inches less than the smallest Indian 

 skull heretofore described. But more extraordinary still is the ap- 

 proximation of the temporal ridges. While in ordinary crania the 

 separation of these ridges is usually from three to four inches, and 

 never less than two inches, in this unique skull from the Detroit River 

 mound the ridges in question approach within three-quarters of an 

 inch, in this respect, as Wyman says, presenting the same condition 

 as that of the chimpanzee. A rounded median crest can be distinctly 

 seen and felt between these ridges, and the skull is markedly depressed 

 on each side for the passage of the powerful mastoid muscles. 



Is this, too, a case of partial reversion ? Such extraordinary forms 

 as the Neanderthal and Engis skulls, and the one above cited, with 

 the La Naulette and other lower jaws, could not have been un- 

 common in those early days, since the chances against finding them 

 1 " Seventh Annual Report of the Peabody Archaeological Museum." 



