132 THE GARDEN AND FIELD. 



# Pottltry Notes P 



An Important Discovery. 



THE " KEY " TO THE LAYER. 



We have from time to time express- 

 ed the opinion that excellent as lay- 

 ing competitions are in many respects 

 they have quite failed to give any 

 guidance in respect to breeding a 

 layer, or only the negative result, 

 that, contrary to all theory — breeding 

 from heavy laying hens was in itself 

 quite ineffectual in obtaining any per- 

 manent improvement in a flock or 

 strain. One had only to look at the 

 up-and-down performances of indivi- 

 dual breeders, and the fact that gene- 

 ral averages show no improvement 

 for some years past to recognise how 

 badly this theory had Isroken down. 

 It is a^ cold, discouraging fact that 

 selected hens of this and other States 

 were just as good five years ago as 

 they are to-day, and considering the 

 thousands of pounds and the immense 

 amount of work put into the job 

 this utter failure to make any pro- 

 gress has no doubt been extremely 

 disappointing to those most inter- 

 ested. 



It is true that these results only 

 confirmed the findings of experimen- 

 tal work in other parts of the world, 

 but even amongst those who followed 

 what was being done at Maine Ex- 

 periment Station and elsewhere, the 

 conclusion arrived at, that- on the ave- 

 rage an inferior layer was a rather 

 better bird to breed from than a good 

 layer seemed too absurd to be cre- 

 dited. 



To those who have studied the 

 f|uestion of inheritance it has seemed 

 that there must be some, hitherto 

 unguessed at, but dominating factor 

 in Ijreeding, which would, when 

 found, prove to be the key to the 

 breeding of consistently good layers, 

 in which selection has so completely 

 failed. It appears now that this long- 

 sought-for key has been discovered by 

 Dr. Raymond Pearl, whose report of 

 the earlier work of the Maine Experi- 

 ment we have been publishing in re- 

 icnt issues. In a word, this key is 

 tlie cock bird. 



It has, of course, long been known 

 that the male exercised considerable 

 influen.ee on his stock, and more or 

 less vague lines of inheritance have 

 been suggested, but little or no ex- 



perimental evidence even has been 

 forth coming. Dr. Pearl has, however, 

 arrived at the conclusion, supported 

 by an array of ascertained facts, that 

 the male bird is solely responsible 

 for the laying of the pullets got by 

 him, and that their inherited capacity 

 for egg production will not be influ- 

 enced by the hen from which they are 

 bred. 



Dr. Pearl's work may be divided in- 

 to three parts. First, he eliminated 

 the good hen as a controlling factor 

 in improvement. Secondly, he dis- 

 covered that certain families invari- 

 ably bred true to either high or low 

 production. Thirdly, and incidental 

 to this, he has satisfied himself that 

 the transmission of fecundity (egg 

 production) is an attribute of the male 

 only. 



A fact of additional interest and im- 

 portance is that Dr. Pearl finds that 

 the incidence of descent as shown by 

 his results, closely follows the Men- 

 delian laws of inheritance. It is not 

 necessary at this time to refer further 

 to this than to remind readers that 

 expressed in the most simple lan- 

 guage, this means, that male birds 

 may be either pure dominants, impure 

 dominants, or recessive in this quality. 

 In pure dominants all the pullets will 

 inherit from the mother of the cock. 

 In impure dominants, descent will fol- 

 low on Mendelian F2 generation 

 lines; that is, 75 per cent, will inherit 

 from the mother of the cock. In 

 recessives none will do so. These 

 figures are, of course, arbitrary and 

 theoretical. They are confirmed in 

 other Mendelian work, but in practi- 

 cal would be subject to apparent but 

 not necessarily real variation, especi- 

 ally in the impure dominants. 



— Fact not Theor3^ — 



Poultry breeders generally are, we 

 know, rather shy of the word Men- 

 dalism and all it means, for after one 

 passes its most elementary stages, its 

 nomenclature and phraseology are un- 

 avoidably cumbersome, and the pos- 

 sil)ility of its practical application, ex- 

 cept in certain external and structural 

 points, has been nil. Hence, the com- 

 mon and reasonable dismissal of the 

 subject as not practical. The fact that 

 Dr. Pearl's conclusions are based on 

 the result of scores, probably hnn- 

 drtds, of tests, in which many thou- 

 sands of birds have been used, should 



August, 1913 



clear the air of the "only theory" 

 idea. It is a case in which indepen- 

 dent experiment and ascertained facts 

 lend confirmation to a theory, and not 

 one in which a theory has been built 

 up around a fact. Dr. Pear,l has 

 throughout dealt with "what is," not 

 "what ought to be," and if the "is" 

 and the "ought to be" happen to 

 closely coincide, it is a happy acci- 

 dent rather than a sought for end. In 

 other words. Dr. Pearl did not set 

 out to prove the truth, or value, of 

 Mendalism, but to discover the secret 

 of breeding a la/cr, and from the 

 evidence before us it appears that he 

 has done so. It is not necessary to 

 know Mendalism to take advantage 

 of it. Briefly expressed, it is: — Find 

 the dominant cock. The phrase re- 

 minds us that the term dominance 

 was freely but loosely used in poultry 

 discussions some few years ago. It 

 is not, perhaps necessary to point out 

 there is a very considerable difference 

 between the two. In the one it was 

 a case of sex, or individual domin- 

 ance, in the present acceptation of the 

 word, the bird is dominant in the 

 characteristics of the hen from which 

 he was bred. We should like to dis- 

 associate the theory we are now dis- 

 cussing, as much as possible from 

 scientific breeding, which is such a 

 bugbear to many breeders. It is of 

 immense interest to the man of 

 science, but do not let us forget that 

 it is also of great importance to the 

 man of the poultry yard and the 

 breeding pen. 



Dr. Pearl is first a scientist, and 

 then a poultry breeder, and his first 

 announcement has been made in a 

 scientific journal, of which article we 

 have merely an outline, but a full 

 statement and discussion of the theory 

 advanced, in its practical application, 

 will shortly, no doubt, be submitted 

 for the information of breeders, and 

 this we sliall receive in due course. 



— How to use the Key. — 

 We have been writing against time, 

 and the expostulations of a somewhat 

 irate printer, whos< ideas on the sub- 

 ject of sending in "copy" are not very 

 elastic. We end our sermon, instead 

 of beginning it, with a text. It is: — 

 Find till' dominant male— and again 

 — Find the dominant male. To this 

 end we can recommend the trap nest 

 and the single testing pen with a 

 clearer conscience as to their real 

 utility, than has been the case for the 

 last few years. The following occur 

 to us as pretty obvious first steps in 

 finding him. Test every pullet, irre- 

 spective of the hen she was bred 



