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dark lines, possibly the result of somewhat similar markings in 
the char. But it is remarkable that they do not approach the 
colours of any of our fresh water fishes, which one would 
imagine ought to be the case if external colours are greatly 
determined by local surroundings. 
Among the fiat fishes, or Pleuronectide, hybrids have been 
observed between the flounder, Plewronectes flesus, and the dab, 
P. limanda ; between the plaice, P. platessa, and the turbot, 
Rhombus maximus ; and between the turbot and the brill, R. 
levis. Now, as all these instances occurred among these sea 
fishes in a wild state, partial domestication cannot be brought 
forward as an agent. 
Numerous as are the foregoing instances of hybridization 
among domesticated, semi-domesticated, and wild animals, they 
are merely a selection out of many which I have collected. 
Unless their correctness is disputed, how, I might ask, can we 
be expected to accept the conclusions of certain authorities 
in zoology (1) that species belonging to two distinct genera 
cannot cross; (2) that species belonging to two distinct families 
are unable to breed together; (3) that the fertility of hybrids 
does not extend to the second generation. I have, I believe, 
made it evident that many animals belonging to the distinct 
species of the same genus will cross, as, among mammals, the 
black bear and brown bear, tiger and jaguar, jaguar and 
leopard, Mexican jaguar and common jaguar, tiger and lion, 
zebu and yak, zebu and gayal, Huropean domestic ox and gayal, 
chamois and domestic goat, moufflon and domestic sheep, horses 
and asses, zebra and ass, mare and quagga. Among birds, two 
species of crowned pigeons (Gowra), common pheasant and ring- 
necked pheasant, common and silver pheasant, capercailie and 
black grouse, black swan and white swan, Chinese and common 
goose, barnicle and white-fronted wild goose, collared duck and 
pochard, pochard and castanaceous duck, blackbird and thrush. 
Among fish, herring and pilchard, salmon and trout, English and 
American char, flounder and dab, turbot and brill, tench and 
common carp, trout and char, Californian salmon and American 
char, grayling and trout, plaice and turbot. 
