The foregoing remarks on the effects of domestication seem to have been inspired by those given p. 123 and pp. 168, 169 of this volume.[280]
"Some, doubtless, have changed less than others, owing to their having undergone a less protracted domestication, and a less degree of change in climate; nevertheless, though our ducks and geese, for example, are of the same type as their wild progenitors, they have lost the power of long and sustained flight, and have become in other respects considerably modified.[281]
"A bird, after having been kept five or six years in a cage, cannot on being liberated fly like its brethren which have been always free. Such a change in a single lifetime has not effected any transmissible modification of type; but captivity, continued during many successive generations, would undoubtedly do so. If to the effects of captivity there be added also those of changed climate, changed food, and changed actions for the purpose of laying hold of food, these, united together and become constant, would in the course of time develop an entirely new breed."
This, again, is almost identical with the passage from Buffon,[282] p. 148 of this volume. See also pp. 169, 170.
"Where can our many domestic breeds of dogs be found in a wild state? Where are our bulldogs, greyhounds, spaniels, and lapdogs, breeds presenting differences which, in wild animals, would be certainly called specific? These are all descended from an animal nearly allied to the wolf, if not from the wolf itself. Such an animal was domesticated by early man, taken at successive intervals into widely different climates, trained to different habits, carried by man in his migrations as a precious capital into the most distant countries, and crossed from time to time with other breeds which had been developed in similar ways. Hence our present multiform breeds."[283]
Here, also, it is impossible to forget Buffon's passages on the dog, given pp. 121, 122. See also p. 223.
"Observe the gradations which are found between the _ranunculus aquatilis_ and the _ranunculus hederaceus_: the latter--a land plant--resembles those parts of the former which grow above the surface of the water, but not those that grow beneath it.[284]