[329] In the spring of 1862 I obtained permission from the Director-General of the Medical department of the Army, to transmit to the surgeons of the various regiments on foreign service a blank table, with the following appended remarks, but I have received no returns. “As several well-marked cases have been recorded with our domestic animals of a relation between the colour of the dermal appendages and the constitution; and it being notorious that there is some limited degree of relation between the colour of the races of man and the climate inhabited by them; the following investigation seems worth consideration. Namely, whether there is any relation in Europeans between the colour of their hair, and their liability to the diseases of tropical countries. If the surgeons of the several regiments, when stationed in unhealthy tropical districts, would be so good as first to count, as a standard of comparison, how many men, in the force whence the sick are drawn, have dark and light-coloured hair, and hair of intermediate or doubtful tints; and if a similar account were kept by the same medical gentlemen, of all the men who suffered from malarious and yellow fevers, or from dysentery, it would soon be apparent, after some thousand cases had been tabulated, whether there exists any relation between the colour of the hair and constitutional liability to tropical diseases. Perhaps no such relation would be discovered, but the investigation is well worth making. In case any positive result were obtained, it might be of some practical use in selecting men for any particular service. Theoretically the result would be of high interest, as indicating one means by which a race of men inhabiting from a remote period an unhealthy tropical climate, might have become dark-coloured by the better preservation of dark-haired or dark-complexioned individuals during a long succession of generations.”
[330] ‘Anthropological Review,’ Jan. 1866, p. xxi.
[331] See, for instance, Quatrefages (‘Revue des Cours Scientifiques,’ Oct. 10, 1868, p. 724) on the effects of residence in Abyssinia and Arabia, and other analogous cases. Dr. Rolle (‘Der Mensch, seine Abstammung,’ &c., 1865, s. 99) states, on the authority of Khanikof, that the greater number of German families settled in Georgia, have acquired in the course of two generations dark hair and eyes. Mr. D. Forbes informs me that the Quichuas in the Andes vary greatly in colour, according to the position of the valleys inhabited by them.
[332] Harlan, ‘Medical Researches,’ p. 532. Quatrefages (‘Unité de l’Espèce Humaine,’ 1861, p. 128) has collected much evidence on this head.
[333] See Prof. Schaaffhausen, translat. in ‘Anthropological Review,’ Oct. 1868, p. 429.
[334] Mr. Catlin states (‘N. American Indians,’ 3rd edit. 1842, vol. i. p. 49) that in the whole tribe of the Mandans, about one in ten or twelve of the members of all ages and both sexes have bright silvery grey hair, which is hereditary. Now this hair is as coarse and harsh as that of a horse’s mane, whilst the hair of other colours is fine and soft.
[335] On the odour of the skin, Godron, ‘Sur l’Espèce,’ tom. ii. p. 217. On the pores in the skin, Dr. Wilckens, ‘Die Aufgaben der landwirth. Zootechnik,’ 1869, s. 7.
[336] Westwood, ‘Modern Class. of Insects,’ vol. ii. 1810, p. 541. In regard to the statement about Tanais, mentioned below, I am indebted to Fritz Müller.
[337] Kirby and Spence, ‘Introduction to Entomology,’ vol. iii. 1826, p. 309.
[338] Even with those of plants in which the sexes are separate, the male flowers are generally mature before the female. Many hermaphrodite plants are, as first shewn by C. K. Sprengel, dichogamous; that is, their male and female organs are not ready at the same time, so that they cannot be self-fertilised. Now with such plants the pollen is generally mature in the same flower before the stigma, though there are some exceptional species in which the female organs are mature before the male.