200 



CANARIES, HYBRIDS, AND BRITISH BIRDS 



afterwards differiiio' I'rum what lKi])|»cns to 

 their brothers and sisters. 



" Of course, we are all familiar with this 

 ' conoeiiital or innate variation ' as shown 

 by brothers and sisters in human families. 

 How and why does iimate variation arise ? 

 It arises from chemical and mechanical 

 action u]ion the ' jjerms ' or reproductive 

 cells, contained in the body of the ])arents. 

 and also sometimes from the mating' in 

 reproduction of two strains or races which 

 are already dilTercnt from (/nc another, 

 ^Vheu an animal or plant is ijiven unaccus- 

 tomed food or broujiht uj) in new surround- 

 ings (as, for instance, in captivity), its 

 germs are affected, and they produce 

 variations in the next generation more 

 abundantly. The best analogy for what 

 occurs is that of a ' shaking up ' or dis- 

 turbance of the particles of the germ or 

 reproductive material, somewhat as the 

 beads and bits of glass in a kaleidoscope 

 arc shaken and change from one well- 

 balanced arrangement to another. The 

 same aiialogv aj)|ilies to the crossing or 

 fertilising of one ' strain " or ' race " by 

 dilTei'ing froiu it. A disturbance is the 

 conscciuence, and a de])arture in the form 

 and character of the young from anything 

 arrived at before often takes place. These 

 variations have no necessary fitness or 

 correspondence to the changcK:! conditions 

 which have jiroduccd them. They are, so 

 to speak, de])artures in all and every direc- 

 tion—not very great, hut still great enough 

 to be selected hy sui'\iv:d if occui-ring in 

 wild, extra-human nature, and obvious 

 enough when ))r()(luced in cultivated animals 

 ••md |il;inls to he seen and selected b\' man. 

 the stock breeder or fancier. Indeed, the 

 stock breeder and horticulturist go to work 

 in this way dcliherately. 'J'hus they get 

 olTspring j)ro<lueed which show strange and 

 miexpccted variations of man\' kinds new 

 feathers, new colours, length of limb all 

 kinds of variation. I'roni the congenital 

 varieties thus produced by " stirring up,' 

 'breaking down.' or disl iirbing the germ 

 matter (germ ])lasm) of the parents, the 

 breeder next ])rocccds to select and male 

 those wliieli show the character which suits 



his fancy, whilst he rejects the others. Thus 

 he establishes and, by repeated selection in 

 every generation, maintains, and, if he 

 desires, increases the characteristics which 

 he values. 



■" Birth-variation is. then, an inherent 

 quality of living things (including man) as 

 much as heredity, which is the name for 

 the (juality ex]>ressed in the resemblance 

 of offsjiring to ])arcut. \Vhat happens, 

 then, when there is a cessation of selection ? 

 All sorts of birth-variations appear and 

 grow UJ)."" 



This is yearly \erified in the breeding 

 of our Canaries. The great i)ower of this 

 ])rinci])le of selection is not hyjiothetical, 

 it is certain ; an animal's organisation is 

 something quite plastic, which can be 

 modelled almost as one pleases, within 

 reason, in the hands of careful l)reeders 

 who know their work. 



Mr. Lewis Wright, in his " Book of 

 Poidtry," clearly showed the force of selec- 

 tion. In dealing with pedi- 



Lewis gree he took as an illus- 



Wright on 4. .■ .1 v 



c , .. tration the ai)pearance ol 



Selection. ' ' 



a fifth toe in one or two 

 chickens, in a variety in which that pecu- 

 liarity does not naturally exist, but which 

 luight have arisen from some remote taint, 

 and showed what might be done by breed- 

 ing from one of these chickens. "" If one 

 of these chickens be bred from, it is probable 

 that a few of her ]irogeny, but still few, 

 will also show this lifth toe: the greater 

 pari, however, re\'ei'tiiig to what \vc may 

 call the usual type of the yard. If we 

 mate this hen to a, cock showing the 

 tendency in the same w.-iw the number of 

 five-toed proginy will be somewhat in- 

 creased : but still, supposing there is no 

 apj)recial)le t;iiiil in the y.iril, they will 

 n<it be many, and the four-toed chickens 

 they produced will have little tendency 

 to breed birds with five toes. IJut now 

 suppose we select froni the chickens pro- 

 duced fi'om these two li\e toed j)arents a 

 ))air also live-toed, and breed //;(■»(. together. 

 We shall now lind the tendency \'astly 

 increased —so much so, that very likely a 

 full half of the produce will be five-toed, 



