126 The Illustrated Book of Poultry. 



Having shown that the common slaty-bkie dovecot pigeon is almost certainly the ancestor of all the 

 varieties, he shows that many breeds when crossed are continually producing pigeons coloured more 

 or less like it, and often identical in colour, though the breeds themselves have been kept pure 

 beyond the memory of man. Similarly, many breeds of fowl when crossed continually produce 

 the reddish-brown plumage of the Gallits Baiikiva, which is by most naturalists now regarded as 

 the ancient progenitor of our domestic breeds. Again, the White Aylesbury drake and a Black 

 Labrador duck produced a bird coloured like the mallard. Similar instances are quoted in regard 

 to cattle ; and in regard to the horse, reason having been given for the opinion that the original of 

 all the equine races was some one animal striped like the zebra, it is shown that the produce of the 

 horse and ass when crossed, and so extensively bred in Spain and America, have a strong tendency 

 to develop stripes, especially on the legs. " It would appear," adds Mr. Darwin, "that with crossed 

 animals a similar tendency to the recovery of lost characters holds good even with instincts, since 

 so many cases have been recorded of the crossed offspring from two races, neither of which are 

 incubators, becoming first-rate sitters, that the reappearance of this instinct must be attributed to 

 reversion from crossing."* 



The extent to which hereditary peculiarities may lie dormant in a strain, and be therefore 

 capable of revival under this or any other stimulus, is one of the most surprising facts in physio- 

 logical science, and still more occult manifestations of it have been specially remarked upon by 

 Mr. Darwin, under the name of " latent characters." That eminent naturalist mentions as one of 

 the most remarkable instances of this the Sebright Bantam. In this breed the sickles of the male 

 bird have long been lost, and that peculiarity has now become so strongly established that even 

 repeated crosses with the Black Bantam have little impaired it. Yet on the rare occasions in which 

 a Sebright hen becomes barren, and, as then usually happens, begins to crow and assume other 

 peculiarities of the male bird, she generally acquires full sickle feathers, showing that however long 

 and entirely lost, some tendency to that characteristic male feature yet remains latent in the breed. 



We have endeavoured to explain this principle fully, because its immediate bearing upon the 

 operations of the breeding-yard is most important. This we shall readily see by a few illustrations. 

 There is, for instance, a well-known strain of Buff Cochins, of marked excellence in every point, but 

 which has a strong tendency to breed a white feather in the cock's tail. Now it is perfectly possible 

 by a judicious cross from some other strain, and careful selection afterwards, to get rid of this 

 objectionable feature ; and we will suppose an individual yard in which this has been so far 

 accomplished that in only a small proportion does the hated white feather appear. This desired 

 result, with a little care, will now be easily maintained while such a yard is bred to itself or with 

 any other not too far removed from it in blood ; but if crossed from a strain flio roughly distinct and 

 alien, or what poultry-men call too "sudden" a cross (for without knowing the reason, they have 

 found the evil of such often, and know it well), the olel white feather may very probably reappear in 

 all its original strength, though the new blood contained no tendency to it whatever. It is simply 

 i/ie cross of strange blood which gives the impulse to reversion. In the same way, to take the case 

 mentioned just now, the pure white Spanish face being simply the result of assiduous breeding, and 

 the most extreme care being needed for its preservation, the simple fact of crossing two entirely 

 distinct strains gives the impulse to revert to the red face which belonged to the Minorca — in all 

 probability the original breed from which it was derived. We need not illustrate this point further, 

 as tne same principle will readily explain many other anomalies which have long puzzled amateurs. 



* In our last chapter we gave another illustration of the same fact in the recovery of economic characteristics, but not carried 

 so far back. 



