2. Changes produced by differences of climate and even seasons. Thus "the sheep of warm climates are covered with hair instead of wool, and the hares and partridges of the latitudes which are long buried in snow become white during the winter months" (p. 234). Only a passing reference is made to this factor, and the effects of domestication are but cursorily referred to. In this respect Darwin's views differed much from Buffon's, with whom they were the primary causes in the modification of animals. The other factors or agencies are not referred to by Buffon, showing that Darwin was not indebted to Buffon, but thought out the matter in his own independent way. 3. "Fifthly, from their first rudiment or primordium to the termination of their lives, all animals undergo perpetual transformations, which are in part produced by their own exertions in consequence of their desires and aversions, of their pleasures and their pains, or of irritations or of associations; and many of these acquired forms or propensities are transmitted to their posterity" (p. 237). The three great objects of desire are, he says, "lust, hunger, and security" (p. 237). 4. Contests of the males for the possession of the females, or law of battle. Under the head of desire he dwells on the desire of the male for the exclusive possession of the female; and "these have acquired weapons to combat each other for this purpose," as the very thick, shield-like horny skin on the shoulders of the boar, and his tusks, the horns of the stag, the spurs of cocks and quails. "The final cause," he says, "of this contest among the males seems to be that the strongest and most active animal should propagate the species, which should thence become improved" (p. 238). This savors so strongly of sexual selection that we wonder very much that Charles Darwin repudiated it as "erroneous." It is not mentioned by Lamarck, nor is Dr. Darwin's statement of the exertions and desires of animals at all similar to Lamarck's, who could not have borrowed his ideas on appetency from Darwin or any other predecessor. 5. The transmission of characters acquired during the lifetime of the parent. This is suggested in the following crude way: