Reports to the Evolution Committee of the Royal Society. 1-5.

Date:
1902-1910
Catalogue details

Licence: In copyright

Credit: Reports to the Evolution Committee of the Royal Society. 1-5. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    510/526 (page 70)
    individuiils of generation Fi inter se there would be agoutis, blacks, cinuamons, chocolates, dark-eyed and ruby-eyed reds. If, instead of mating the blacks of Fi inter se we mate them with ruby-eyed red carrying g, we shall get the above-mentioned colours in equal numbers, viz., blacks, chocolates, dark- and ruby-eyed reds. The actual numbers obtained are given in the two preceding tables. If we mate the Fi agoutis of this cross with red or cream, the result depends on whether or not the red or cream carries G or g or both. If it carries g, the offspring will be equal numbers of agoutis, blacks, cinnamons, chocolates, dark-eyed reds heterozygous in Gg, dark-eyed reds homozygous in g, ruby-eyed reds heterozygous in Gg, and ruby- eyed reds homozygous in g. If it is not known whether the reds carry G or g, the results of this cross still have value if we deal with the sum of the agoutis and blacks and the sum of the cinnamons and chocolates:— Parents (neglecting dilution). Offspring (neglecting dilution). Agouti F, from black X ruby- eyed red. Ruby-eyed red. Agouti. a W Cinnamon. Cliocolate. Red, dark-eyed. <u (U (Albino.) 483 ^ 483 <? 483 ^ 490? 545 ^ 560? 374? 524? fiOl ? 427 (? 492? 394 cJ 1 1 1 1 1 1 2 1 1 1 1 1 3 1 1 2 Tntnl 2 3 3 2 Totals 5 5 3 5 Equal totals. Supernumerary Mammce. A fairly large number of the guinea-pigs which I have bred have possessed one or two mammae in addition to the normal inguinal pair. Relationship between the original individuals showing this feature cannot be proved, though it is quite possible that it exists, in some remote degree, as all of them have some of the blood of Roberts' chocolate stock. All these original individuals were bred from normal stock.