[6]

May 4/68/ I wd accept Wallace's view about Birds did I not remember Pigeons, odd the ♀ sexual limitations in colour shd occur in this group. How are canary Birds in wild & tame states sexually? How fowls differ sexually often less than in wild state & 2 sexes nearly alike — Hen sometimes more. Now in Parrot or Kingfisher or Pigeon group — it is rather odd in my view that the same law of variation & inheritance shd have pervaded so many forms, ie that the variations supervened in any & consequently were transmitted to both sexes, seeing how Fowls & Pigeons differ in this respect — This looks like selection — If ♀ progenitor

[in margin:] Reflect on relation of colour of young cocks to adult to show what time change commences. In Black & white young & both sexes coloured alike.

[6v]

from being acquired by inheritance instinct of nidification in holes, it is not odd shd have been transmitted. It is an awful puzzle how the rule of sexes inherited. It is odd that in some birds males alone seasonally acquire brilliant plumage, & then both sexes acquire it seasonally. How are young in these cases I suppose like ♀ This case holds for protection Then give Squacco Herons In Tringæ I suppose young like winter Plumage. In cases when male alone becomes brilliant during breeding season، it might to transmit to males alone, but in Tringæ does transmit to both sexes — The law fails So with these pigeons which change plumage quite late change common to both sexes.

Case of Transmission to opposite sex.