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Show , ,,r- - - " 1 POULTRY ;; APPLIED LAWS OF BREEDING. C. S. Gorlinc. Jt is a tenet of the hypothesis of evolution that the embryo is built up. by the union of organic particles ' which arc given off from every part of the body of the parent, and which, assembling in the sexual secretions, , assume in the body of the offspring positions like those which they occupied' occu-pied' in the parent. (Theory of Hcri-dity Hcri-dity Buffon.) According to Huxley " the hen's egg contains an excessively minute but complete chick, and that fecundation and incubation simply cause this germ to absorb nutritious matters, which arc deposited in the ihlcrcsticcs of the elementary struc-' struc-' turc of which the chick germ is made up. The ovum is a cell containing material particles each of which corresponds cor-responds to a specific characteristic hereditary in that species. Each cell Sdf the body may be considered as an individual, which has the power to J grow and to give rise by -division to similar cells and to throw off minute germs. During the evolution of the species, these cells acquire by natural-selection natural-selection specific functions adapted to the requirements of their environment. environ-ment. So long as the conditions remained re-mained unchanged, they continue to perform their proper functions as a part of the body; but, when tho conditions con-ditions arc changed, and these func tions disturbed so that the conditions 2 of, life ibecomc unfavorable, these "i germs begin to throw off small par- ficles which are termed gcmmulcs of that particular cell. These gcmmulcs may be carried to every part of the body and may penetrate to an ovarian ovar-ian ovum, an which case the gemmulc will unite with an impregnate that particle of the ovum which will give . rise in the progeny to the cell which corresponds to the one which produced pro-duced the gemmule; or, it may unite with a closely related particle giving rise to a closely related cell. When t a cell thrown of a gemmule becomes tk developed in the body of the offspring it will be a hybrid, and variation will be the result, and the next genera- .. Jtion will share by direcf inheritance the tendency to vary, for a cell thus varied will continue to throw off gcrnmules and m thus transmit variability varia-bility to the corresponding part in the bodies of successive generations of descendents until such time as J favorable variation is grasped by natural na-tural selection. With the unchanged environment, the ovum which produced pro-duced the organism thus selected will transmit the same variation to its ovarian ova by direct inheritance, the characteristic will be established as an-hereditary race characteristic ami will be perpetuated and transmitted by the selected individuals and their descendants, without gcmmulcs. v It will thus ibe noted that the occurrence oc-currence of variation is due to change in environment, causing a cell to throw off gcmmulcs, and thus transmit trans-mit to descendants a tendency to vary in the part which is affected by the change. "The scries of changes in tho hen's egg gives us an outline sketch of the scries of ancestors. This ancestral or Phylogcnetic significance sig-nificance of the phenomena of onto geny or individual development is up to the present time the only explanation explana-tion of the latter." ("Gcsammcltc Popularc Vortragc," II., . p. 103.) Thus we accept the basic law of cm-bryology cm-bryology that "Individual development develop-ment is a recapitulation of the evolution evo-lution of the species." From a. careful study of the foregoing, fore-going, we should' be able to arrive at an understanding of the ninth principle prin-ciple of breeding: "Peculiarities of direct heredity arc transmitted to the progeny generally from the more vig orous parent." We should also be able to appreciate the importance of heading our selected jien with a vigorous vig-orous typical male, for unless the male and females arc of the same blood lines, although of the same species, the result of their union will be a cross and while there can be no doubt that what the two sexes play similar parts in transmitting characteristics, charac-teristics, yet experience has shown that the male gcmmulcs in every cross arc predominant. Perhaps the most common and well known is the cross , between the ass and a marc in which the mule inherits more particularly 'he type of the ass, while in a reciprocal recip-rocal cross between a stallion and) a she-ass, the hinney inherits the type of the horse in the head, ears, legs and Toice which instead of a bray, as in the mule, becomes the ordinary neigh of the horse. We quote from Darwin: "The silk 4 fowl breeds true, and thc$c' lfaon to believe that it istf vcrylmcicht , race; but when I reared a large number num-ber of mongrels from a silk hen by a Spanish cock, not one exhibited even a trace of the so-called silki ncss," In a number of instances, we crossedDominique hens with a common com-mon cock and the chicks were invariably invari-ably alt mongrel colors, while the progeny of a cross between a Light Brahma cock and common hens were like the cock-bird iri coloring and feathering, even to the toe feathers. In a cross between a Barred Rock cock and a White Orpington hen, 'the chicks were typical Rocks, but in color col-or quite light. A cross between a Black Langshan cock and a White Rock hen produced black chicks. The above illustrations will give us an idea of the importance of selecting select-ing both male and females for the breeding pen from birds that are of the same blood line if we would avoid troublesome variations that are otherwise sure to be transmitted through the male gcmmulcs, for gcmmulcs gcm-mulcs which arc formed in the male body are more likely to be transmitted transmit-ted to descendants than those which .develop in the female body. Thus the feathering, color and comb presented pre-sented by the male in our selected pen should be as nearly standard as possible if wc would reproduce this excellence in the progeny, while with the same blood lines in the females, we would expect to perpetuate size and general type, Principle VI. It will thus be noted that males arc more variable than females, and that variations varia-tions in the progeny will more likely like-ly develop the male characteristics, especially where blood-lines are crossed. It will also be noted that a tendency ten-dency to reversion is more apt to make its appearance as the result of a cross and thus we have Principle VIII: "Peculiarities of revcrsiorial hcrqdity make their appearance in alternate generations." These mani-. mani-. festations of revision may lay dormant for many generations but wc have seen from the foregoing that any change of environment that will disturb the functions of the germ cell will cause the cell to throw off 'gcmmulcs and ordinarily these gcmmules will germinate ger-minate and reproduce their latent characteristics 'in alternate generations. genera-tions. These reverslonal ifcciilifrH- . ' 7t V J? v w H ties of heredity may ibe latent for mm- M dreds of generations, but when a dis- M turbance of theffinctions of that par- M ticular germ arises, a gemmule is H thrown off and the peculiarity ap- M pears, but is rarely transmitted from H father to son. Breeders of Buff and M While Orpingtons occasionally pro- fl ducc chicks with feathers upon the M shanks. When it is remembered that M Orpintons arc hybrids, and that the M Cochin h a remote ancestor, it will M at once be understood that this pe- M culiarity is an instance of reversion. M Breeders- of White Wyandottes are M aware that that variety is evolved H from sports of the Silvers and is H cimply a variation, the result of for- H mer crossing. Note then, the differ- H ence between reversion and variation. H The one is the development of a pe- H culiarity of remote ancestry; the oth- M cr is the development of oi peculiar- M ity not common to remote ancestry. M Either effect may be produced by a H change of environment; and one or H both may result from crossing. M If wc mate up a pen with a male M of one blood-line with females of an- M other blood-line, in practice the pro- M geny will be an out-cross, and here H wc will have a further tendency to M reversion and variation, hence Prin- M ciple X: "Cross heredity is the result H of an out-cross." This form of trans- M mission usually occurs also in alter- M nate encrations, but may be trans- mittcd directly from sire to daughter jM ro fromi dam to son. The practice of "introducing new blood" which was .M once quite common is now avoided M by the experienced' breeder, as intro- M ducing new blood generally under- jH stood means the crossing of two dis- .M tinct blood-lines. However, the in- troduction of new blood may be ac- H complished-in another way, as will (H be shown further on, without the haz- ! ard of cross heredity. lM |