THE SENSE ORGANS 147 
THE PROJECTILE NOSE 
Whereas the olfactory ridges and Jacobson’s organ of Man 
are to be considered degenerate, the projectile nose and its 
skeletogenous supports are in a progressive condition; they may 
indeed be considered as specifically human structures. It cannot 
as yet be said with certainty what gave the first impulse to their 
Ss . 
SSS 
i 
: 
z 
SSS 
EEDA 
Fic. 90.—HEADS oF TWO HuMAN EMBRYOS. 
A, at the end of the second; B, at the beginning of the third month (after W. His). 
au., external auditory involution, with the pinna (p.) seen developing around it. vs., 
eye; ol., nose. 
development. This question awaits an extended morphological 
inquiry.! 
THE EYE 
The human eye itself shows few vestigial structures; and 
these, being limited to the embryo, are but transitory. I refer 
to the arteria hyaloidea which passes through the vitreous body 
within Cloquet’s canal, and which is closely related to the fcetal 
choroidal fissure. The former plays an important part in the 
nutrition of the central part of the eye during embryonic life. 
This is provided for in Fishes and Reptiles by organs known as 
1 This has been undertaken by my pupil F. Spurgat, and a preliminary report on 
his first series of observations will be found in the Anat. Anzeiger, Bd. viii. p. 228. 
