The Tinochorus is closely related to some other South American birds. Two species of the genus Attagis are in almost every respect ptarmigans in their habits; one lives in Tierra del Fuego, above the limits of the forest land; and the other just beneath the snow-line on the Cordillera of Central Chile. A bird of another closely allied genus, Chionis alba, is an inhabitant of the antarctic regions; it feeds on sea-weed and shells on the tidal... more...

Enamel and Dentine.—As the secretion decalcified ordinary bone, I determined to try whether it would act on enamel and dentine, but did not expect that it would succeed with so hard a substance as enamel. Dr. Klein gave me some thin transverse slices of the canine tooth of a dog; small angular fragments of which were placed on four leaves; and these were examined each succeeding day at the same hour. The results are, I think, worth giving... more...

LETTER 378. J.D. HOOKER TO CHARLES DARWIN. Kew, January 20th, 1867. Prof. Miquel, of Utrecht, begs me to ask you for your carte, and offers his in return. I grieve to bother you on such a subject. I am sick and tired of this carte correspondence. I cannot conceive what Humboldt's Pyrenean violet is: no such is mentioned in Webb, and no alpine one at all. I am sorry I forgot to mention the stronger African affinity of the eastern Canary Islands.... more...

INTRODUCTION We know from the contents of Charles Darwin’s Note Book of 1837 that he was at that time a convinced Evolutionist. Nor can there be any doubt that, when he started on board the Beagle, such opinions as he had were on the side of immutability. When therefore did the current of his thoughts begin to set in the direction of Evolution? We have first to consider the factors that made for such a change. On his departure in 1831,... more...

After having been twice driven back by heavy south-western gales, Her Majesty's ship Beagle" a ten-gun brig, under the command of Captain Fitz Roy, R.N., sailed from Devonport on the 27th of December, 1831. The object of the expedition was to complete the survey of Patagonia and Tierra del Fuego, commenced under Captain King in 1826 to 1830--to survey the shores of Chile, Peru, and of some islands in the Pacific--and to carry a chain of... more...