a long neck because his ancestors used their necks to reach food, while the snake lacks legs because his ancestors crawled on their bellies until their legs disappeared. This was the theory of "inheritance of acquired characters"—a theory sponsored by Darwin's grandfather, and which even today is far from being settled either favorably or otherwise.
So far as we can tell, Lamarck did not go far to convince Charles Darwin that species were the product of natural forces, nor did he furnish much material for the young naturalist's study. Indeed, it seems probable that Darwin did not read Lamarck's books in the original French, for he had great difficulty with the language. This, perhaps, accounts for the slighting and even contemptuous references to the books which one may find in several of the letters. In the second edition of the Journal of Researches, he describes a South American animal, whose habits resemble those of the mole, and which frequently is blind, and comments, "Considering the strictly subterannean habits of the Tucutuco, the blindness, though so common, cannot be a very serious evil . . . . Lamarck would have been delighted with this fact had be known it when speculating (probably with more truth than usual with him) on the gradually acquired blindness of the Aspalax, a gnawer living underground, and of the Proteus, a reptile living in dark caverns filled with water, in both of which animals the eye is in an almost rudimentary state, and is covered with a tendinous membrane of skin. … no-doubt Lamarck would have said that the Tucutuco was passing into the state of
