# 
` phlet on arrow-release, a copy of which he had kindly sent mê, — 
_ held somewhat obliquely, the upper moiety inclining towards í K 
784 General Notes. [Aug 
The facts as interpreted above seem, to me, to leave no doubt $ 
regarding the great influence which variation in the mechanical 
relations of the chorion to the uterine walls has exercised in the — 
evolution of placental types. This, coupled with the influence 
exerted by the varying fertility of species, the variation in the J 
vascularity of different parts of the uterine walls, and the form J 
of the uterine cavity, has, doubtless, been the all-important factor $ 
in the evolution of the various existing types of gestation- f 
John A, Ryder, June 24, 1887. 
ANTHROPOLOGY. 
Arrow-Release among the Navajos.— Yesterday (28th March, 
1887) I was out with my camera upon one of the hills which — 
closely surround the frontier military post of Fort Wingate, New — 
Mexico. On the site referred to are built three Navajo lodges, 
“hogans,” as they are called,—two of the old original structures — 
of the tribe and one of the more, recent dwellings, or plan of 
building. Having made my intentions known, that I desired 4 
picture of a warrior in the act of shooting his war-bow, there 
soon gathered about me some eight or ten venerable-looking old 
Navajo bucks, two or three of whom had their war-bows ; 
arrows with them. 
Having just read with great interest Professor Morse’s pat- 
| it was with no little curiosity that I handed a bow and two of 
three arrows to an old gray-headed warrior present, and asked 
him, “ Draw,—as if you were about to kill the worst enemy you 
had in the whole world.” A particularly savage expression came 
over the old fellow’s countenance at the suddenness of my request, 
ut he seized the bow and arrows, and immediately drew one of 
them to its very head. This is the position he stood in at the 
time: his left foot was slightly in advance of the right, the bow i 
was firmly seized at its middle with the left hand, while it 
right from the vertical line, and, of course, the lower limb having 
a corresponding inclination towards the left side. The two fg 
rrows were held with the bow in the left hand, being COn it 
by the fingers against its right outer aspect. With the right 1 
A th eugak , and consequently including the 
ents Ranger, bore against the string below this 
