Septnmber, 1913 



THE GARDEN AND FIELD. 



186 



productiou be greatly increased. 

 As selection eliminates the physic- 

 ally unlit so will the Mcndel-l'eurl 

 theory eliminate the organically 

 inconiipetent, and the two working 

 hand in hand will tend steadily 

 towards raising! the present average 

 production to the plane of the pre- 

 sent highest production. Vfit in 

 another way ; selection passes out 

 the visibly incompetent, the bar- 

 ren, weakly, structiirallv iaully 

 birds, this new theory when ap- 

 plied will pass out those which 

 are apparently competent, but 

 incompetent to transmit their 

 capacity to their immediate des- 

 cendents. These are the birds 

 which keep down the general aver- 

 ages in laying competitions, which 

 mystify a breeder by kmacking 

 down his 1,500 score of one year 

 to 1,200 the next with birds ot ap- 

 parently, but not really, precisely 

 similar breeding. From what has 

 been written it will be seen that 

 the owner of the very good hen 

 stands to win, not so much be- 

 cause he can convert her descend- 

 ants into better birds but because 

 he can perpetuate her kind withi 

 some certainty. 



— What the Trapnest Says. — 



Dr. Pearl's announcement may be 

 regarded from two distinct pomts 

 of view. First as the experimental 

 proof that (a) the male bird is 

 the controlling factor in egg pro- 

 duction ; (b) his potency is fixed 

 ajid definite ; (c) that within cer- 

 tain limits some males will al- 

 ways beget good stock, that 

 others will beg'et mixed stock. 

 Others had stock (d) that each 

 male (or family of Hue bred males) 

 can be tested through his or their 

 puUets ; (e) that the testing of 

 pullets for the first four months 

 from the date the first comes into 

 lay (provided of course they, are 

 of approximately the same age) 

 is probably, but not certainly, a 



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true index of total production. 

 The above is, we believe, a fair 

 statement of Ur. Pearl's liudings, 

 irrespective of any theory or Men- 

 delian conception of breeding. The 

 man who has " no time " for scien- 

 tilic breeding may, we believe, take 

 them as indisputable facts. lie can 

 use them as his conditions or op- 

 portunities permit or his inclina- 

 tion dictates or — he can leave them 

 alone. To the unprejudiced mind 

 they would appear to be worth 

 testing. We quote in this connec- 

 tion a few of the tests bearing on 

 this subject from the summary of 

 Dr. Pearl's paper in the Journal of 

 the Board of Agriculture. 



— A Base. — 

 It is necessary, at the outset, to 

 have a clear idea as to what is 

 meant by fecundity, and how it 

 shall be measured. Mr. Pearl s con- 

 clusion is that the distinguishing 

 dilierences in egg-prod action De- 

 tween good and bad laying hens 

 occur m the winter period, Oc- 

 tober 1st to March ist. In other 

 words, he found i^for the breeds 

 with which he worxed) that, on 

 the average, there is little differ- 

 ence between one fowl and another 

 in the number of eggs laid in the 

 spring and summer, whereas the 

 differences between strains (.and in- 

 dividuals) in the number of eggs 

 laid during the winter are very 

 marked. Thus, the strain of In- 

 dian Game with which he worj^ed 

 gave an average winter egg pro- 

 duction of less than one-third of 

 that given by a strain of Ply- 

 mouth Rocks. For the purposes 

 of his investigation, therefore, Mr. 

 Pearl adopted the winter egg-pro- 

 duction as the measure of fecundi- 

 ty, and it should be understood 

 that in all subsequent references to 

 fecundity the prctduction for the 

 winter period only is meant. 



It was found that hens can be 

 placed, in three distinct classes : 

 (a) those laying no eggs whatever 

 during the winter period ; (b) 

 those laying under 30 eggs ; and 

 (c) those laying over 30 eggs. 



He found, then, that if he took 

 hens of his third class (those lay- 

 ing 30 eggs and upwards during 

 the winter period) and bred them to 

 certain cocks, none of the daugh- 

 ters showed a laying capacity of 

 over 30 eggs. In other words, hens 

 of high prodi'ictiveness (when mated 

 with certain cocks) were unable to 

 transmit their qualities to their 

 daughters. On the other hand he 

 found that hens of the 30 and, over 

 class, if mated with certain other 

 cocks, gave sometimes all high 

 producers, and, sometimes partly 



high and partly low producers. 

 Again, he found that if he mated 

 certain cocks with hens of zero or 

 low producing capacity, he got 

 all the daughters i)roducing 30 

 eggs and over. As concrete illus- 

 trations of these statements the 

 following figures may be given : — 



(a) To show that a highly pro- 

 ductive hen does not transmit her 

 fecundity to her daughters. One 

 Indian Game cock mated with six 

 Plymouth Rock hens, all laying 30 

 eggs ,and over, produced seventeen 

 hens averaging fourteen eggs and 

 three hens laying no eggs. 



(b) To show that a hen of low 

 fecundity may produce daughters 

 of high fecundity. Three Plymouth 

 Rock cocks, known by previous 

 tests to be getting high laying 

 hens mated with six Plymouth 

 Rock hens laying under thirty eggs 

 produced nine hens averaging filty 

 five eggs and seven hens averag- 

 ing nineteen eggs. 



(c) To show that hens oi high 

 fecundity produce nearly all fecund 

 daughters when properly mated. 

 Nine Plymouth Rock cocks mated 

 with thirty-eight Plymouth Rock 

 hens laying thirty eggs and over 

 produced one hundred and eleven 

 hens averaging fifty-six eggs and 

 six hens averaging twenty eggs. 



(d) To show that certain select- 

 ed cocks win produce practically 

 all fecund daughters, however 

 mated. One Plymouth Rock cock 

 mated with ten Plymouth Rock 

 hens of all classes from zero up- 

 wards produced sixteen hens aver- 

 aging fifty-one eggs and one hen 

 averaging thirty eggs." 



The figures as they stand are, 

 we' think, undoubtedly interesting 

 and instructive, though they may 

 not be absolutely convincing as to 

 the power of the male but it 

 should be remembered that they 

 are merely examples of many. For 

 instance, in the case of the Indian 

 Game, the objection might reason- 



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