Chap. XXVI. ANALOGOUS VARIATION. 349 



to believe that in any of these cases long-lost characters have reappeared 

 and in most of them this certainly has not occurred. 



Three species ofCucurbita have yielded a multitude of races, which cor- 

 respond so closely in character that, as Naudin insists, they may be ar- 

 ranged in an almost strictly parallel series. Several varieties of the melon 

 are interesting from resembling in important characters other species, either 

 of the same genus or of allied genera ; thus, one variety has fruit so like 

 both externally and internally, the fruit of a perfectly distinct species^ 

 namely, the cucumber, as hardly to be distinguished from it ; another has 

 long cylindrical fruit twisting about like a serpent ; in another the seeds 

 adhere to portions of the pulp ; in another the fruit, when ripe, suddenly 

 cracks and falls into pieces; and all these highly remarkable peculia- 

 rities are characteristic of species -belonging to allied genera. We can 

 hardly account for the appearance of so many unusual characters by 

 reversion to a single ancient form; but we must believe that all the 

 members of the family have inherited a nearly similar constitution from an 

 early progenitor. Our cereal and many other plants offer similar cases. 



"With animals we have fewer cases of analogous variation, independently 

 of direct reversion. "We see something of the kind in the resemblance 

 between the short-muzzled races of the dog, such as the pug and bull- 

 dog ; in feather-footed races of the fowl, pigeon, and canary-bird ; in horses 

 of the most different races presenting the same range of colour; in 

 all black-and-tan dogs having tan-coloured eye-spots and feet, but in 

 this latter case reversion may possibly have played a part. Low has 

 remarked 29 that several breeds of cattle are " sheeted,"— that is, have a 

 broad band of white passing round their bodies like a sheet; this character 

 is strongly inherited and sometimes originates from a cross; it may be 

 the first step in reversion to an original or early type, for, as was shown in 

 the third chapter, white cattle with dark ears, feet, and tip of tail formerly 

 existed, and now exist in a feral or semi-feral condition in several 

 quarters of the world. 



Under our second main division, namely, of analogous variations clue 

 to reversion, the best cases are afforded by animals, and by none better 

 than by pigeons. In all the most distinct breeds sub-varieties occa- 

 sionally appear coloured exactly like the parent rock-pigeon, with black 

 wing-bars, white loins, banded tail, &c; and no one can doubt that these 

 characters are simply due to reversion. So with minor details; turbits 

 properly have white tails, but occasionally a bird is born with a dark- 

 coloured and banded tail; pouters properly have white primary wing- 

 feathers, but not rarely a "sword-flighted" bird, that is, one with the 

 few first primaries dark-coloured, appears; and in these cases we have 

 characters proper to the rock-pigeon, but new to the breed, evidently 

 appearing from reversion. In some domestic varieties the wing-bars, 

 instead of being simply black, as in the rock-pigeon, are beautifully 

 edged with different zones of colour, and they then present a striking 

 analogy with the wing-bars in certain natural species of the same family, 

 such as PJiaps cMcoptem ; and this may probably be accounted for by 



29 'Domesticated Animals,' 1845, p. 351. 



