184 



THE GARDEN AND FIELD. 



Sept^ocber, 1913 



XKe Key to tKc Layer. 



. — More about Dr. Pearl's Discovery. — 



F'ollowing our reference last 

 month to Dr. Pearl s reported dis- 

 cover3- in regard to the inheritance 

 of the laying- habit in fowls in its 

 broader conclusions, there are cer- 

 tain modilying and limiting- factors 

 to be considered, and as the sub- 

 je^-t is of great importance and, we 

 believe, of interest to poultry 

 breeders, we propose discussing the 

 subject more in detail. 



Dr. Pearl, as we mentioned last 

 month, is a scientist of interna- 

 tional reputation, and( the theory 

 now advanced is of engrossing in- 

 terest in circles far more extended 

 than those covered by the poultry 

 mdustry. It is not, we believe", 

 too much to say that this discov- 

 er}- marks the most important step 

 forward in the application of the 

 Mendel theory which has yst taken 

 place as regards stock breeding. 

 Hitherto animal breeders have not 

 benefited to the same extent as 

 have plant breeders, for the subject 

 is for various reasons, more com- 

 plex when applied to the animal 

 than to plant life. Animal breed- 

 ers have been able to control cer- 

 tain external characters, coloura- 

 tion, etc., on Mendelian lines, but 

 so far they have not made a 

 horse give speed, a cow milk, a 



sheep wool, a pig pork, or a fowl 

 the one is proved to be possible 

 there is no very apparent reason 

 eggs with greater certainty, yet ii 

 why the othe{s should not be so. 



— What it Aniounts to. — 



The Mame investigation has ex- 

 tended over a period , of ten or 

 twelve years, though Dr. Pearl 

 has only been connected with it 

 lor about half that time, and it is 

 interesting to ask ourselves what 

 is the ultimate contriDution to 

 scientific breeding as a result ol 

 much work and some dollars. It 

 may perhaps be best summed up, 

 in its widest application, as the har- 

 monizing of quantity the variation 

 in animals with the principals of 

 Mendel's law of inheritance, and in 

 particular reference to poultry 

 breeding as the determination ol 

 two Mendelian unit characters and 

 their corresponding absences which, 

 in corelated operation, govern egg 

 production, and their mode of se- 

 gregation and recombination. Not 

 much to the general reader, per- 

 haps, but it opens up imme^ise pos- 

 sibilities. To understand its im- 

 portance one has to get back to 

 the basic facts of reproduction. 



— A Link. — 



For our present purpose we do 

 not have to dip deeply into, biology 

 or stop there long. We ' merely 

 want- to connect, for the benefit 

 of those not previously interested, 

 Mendel's theory with' the known 

 facts of the genesis of each indivi- 

 dual life. Very brielly put each 

 new bfe originates in the fusion of 

 a male cell , with a female cell, 

 which united will contain in embryo 

 the finished product, whether that 

 product is an eel or an elephant, 

 a baby or a bantam. UntU Men- 

 del's discovery was discussed 

 very little was known or even 

 gu«ssed of the interaction of the 

 two parts of the now I'lnited cell. 

 That one did inlluence the other 

 was of course apparent , but whe- 

 ther tills inlluence was variable 

 and spasmodic or perordained and 

 constant in its essential working 

 was not understood,. As is well 

 known, Mendel conducted a long 

 series of experiir^ients with com- 

 mon peas, during which he ob- 

 served certain results. To account 

 for these results he formulated a 

 theory which is now known 

 throughout the world as Mendel's 

 Law of Inheritance, and is ac- 

 cepted as an integral part of 

 scientific breeding. The essential 

 principle of the law may be 

 summed up by, saying that ha, ad- 

 vanced the theory and demonstrat- 

 ed its truth, that each separate 

 male and female cell is made up 

 of pairs of contrasting characteris- 

 tics, which he called " unit char- 

 acters," that these pairs were 

 never both present in the .siame ori- 

 ginal cell and that on union they 

 followed definite laws. The gov- 

 erning rule was that one of each 

 pair of unit characters would be 

 dominant to the other, which he 

 named recessive, further that when 

 interbred, the ratio of dominants 

 to recessive would follow certain 

 definite laws, both as to character 

 and number and do so for all time. 



— Clearing the Ground. — 



First let us clear the ground of 

 any possible misconception as to 

 practical application of this theory. 

 It is not a royal road to excessive 

 individual prod('iction. The amount 

 of " Pearl " theory will add one 

 egg to the result of the mating of 

 any two birds, that is fixed and 

 predetermiuated, at least the mea- 

 sure of inherent capacity is, but it 

 promises a means by which the 

 union of any two birds in which 

 this inherent capacity, is either low 

 or governed by inutually antagon- 

 istic elements, can l)e avoided and 

 consequently the average flock 



Koonoowarra Poultry Farm - Enfield. 



6 minutes' walk from electric tram. 'Phone 273. 



Breeder, Kxhibitor, and Importer of Highest Class 

 BARRED PLYMOUTH ROCKS. WHITE PLYMOUTH ROCKS. 

 WHITE ORPINGTONS RHODE ISLAND REDS. 



WHITE LEGHORNS. . 1 



PEKIN DUCKS. WHITE RUNNER DUCKS. 



(Never beaten in Show Pen). (Wonderful Layers of White Shell Eggs). 

 Stock have won n umerous prizes at Adelaide Leading Shows. 

 Eggs and Stock for Sale in Season. 



For further particulars write — 



P. O. MANUEL, Proprietor. 



For FLOORS, FENCES, and all WOODWORK 



CABOT'S creosote: stains 



Cost less than paint, last longer and look twice as well. The colours 

 are soft, transparent— bringing out the natural beauty of the wood— 

 and the Creosote j)rotects the timber from all decay and Renders It 

 Impervious to White Ants. Obtainable in 10 shades from all 

 Colofir Merchants, or the Sole Agents, 



K I XM <2 «& 00., 



.MAR]>B IKOUGH CHA.MIiKRS, WAY.MOI TH STREIOr, ADKLAIDE. 



