“In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, like a whale, insects in the water. Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.” The statement about the gills which “dropped off by want of use” becomes in the original (p. 191):-- “In the higher vertebrata the branchiæ have wholly disappeared--the slits on the sides of the neck and the loop-like course of the arteries still marking in the embryo their former position.” Although the hypothetical case of the black bear--carefully guarded as it is--does not now appear to us at all extravagant (indeed, in the cleft cheeks of the goat-sucker we have a precisely analogous case), Darwin seems to have thought it unsuitable, probably because it became an easy butt for ignorant ridicule. We find accordingly that in the second and all subsequent editions everything after the word “water” is omitted, while “almost” is inserted before “like a whale.” He was alluding to this passage when he wrote to Lyell (December 22nd, 1859): “Thanks about ‘Bears,’ a word of ill-omen to me.” Furthermore, Andrew Murray[I] says, concerning the sentences as they stand in the first edition:-- “In quoting this, I do not at all mean to give it as a fair illustration of Mr. Darwin’s views. I only refer to it as indicating the extent to which he is prepared to go. The example here given I look upon (as I have reason to know that Mr. Darwin himself does) merely as an extreme and somewhat extravagant illustration, imagined expressly to show in a forcible way how ‘natural selection’ would operate in making a mouth bigger and bigger, because more advantageous.” CHAPTER XX. THE DIFFICULTY WITH WHICH THE “ORIGIN” WAS UNDERSTOOD (_continued_)--VIEWS ON SPONTANEOUS GENERATION. The history of opinion on evolution and natural selection, in the years which followed the publication of the “Origin,” can be traced in the titles of the papers and subjects of discussion at successive meetings of the British Association. In the Presidential Address delivered by Professor Newton to the Biological Section of the Manchester meeting in 1887, there is a most interesting account of the struggles which took place:--