[21]

[Note in another hand:] pp. 160/1

Ch. 4

Utrecht , well known as one of the highest authorities in Europe on vision & on the structure of the eye, has most kindly undertaken the investigation with the aid of the many ingenious mechanisms of modern science, & has published the results.* (15) He shows that during violent expiration the external, intra-ocular & the retro-ocular vessels of the eye are all affected & dilated in two ways, & consequently dilated, namely by the increased pressure of the blood in the arteries, & by the return of

(21

[Note in another hand:] p 161

(21

Ch VI

the blood in the veins being prevented. So that it is certain that Hence the vessels both the arteries & the veins of the eye tend are more or less distended during violent expirations.

to become distended. The evidence in detail another point shows that may be seen in consulted by consulting in Professor Donders valuable paper memoir. But I may mention, on his authority, that the whole eye certainly advances or protrudes a little during each violent expiration & it This is due to the dilatation of the retro-ocular vessels, & might have been expected from the intimate connection of the eye & brain; the latter being known to rise & fall with each respiration respiration, when a portion of the skull has

(14

[Note in another hand:] Desc. of Man p. 114

(14

Ch. 3

found it impossible to get obtain clear evidence on this side of the question, & valid reasons my be urged on the other side, at least as far as the innumerable structures are concerned, which are adapted for special ends. There can, however, be no doubt that changed conditions induce an almost indefinite amount of fluctuating variability, by which the whole organisation is rendered in some degree plastic.

 

(In the United States, above 1,100,000 soldiers, who served in the late war, were measured, & the States in which they were born & reared recorded.*(14) From this wonderfully astonishing number of observations it is proved that local influences of some kind act directly on stature; [& we] further learn the interesting fact that [text pasted over] growth has in

[Descent 1: 115:] volcanic & [text pasted over]

between the Fuegians on the eastern & western coasts of T. del Fuego, it is scarcely possible to avoid the conclusion that better food & greater