HEUMANK. 153 



that in this way the chemical colours may not only be maintained but also 

 strengthened and improved, but of the ways and means in detail, how to achieve 

 this are so far a closed door to me. 



One fact I have settled to my entire satisfaction, and that is that both in- 

 sectivorous and seed-eating birds require a certain amount of live food, which 

 itself has lived upon live plants. They absolutely require this a few months 

 before the moult sets in. I have tried this on Orange Bishops in conjunction 

 with feeding on unripe seed, such as millet or grass-seed still in a milky state. 

 I almost got back the original scarlet colour! Red-breasted Australian' Robins 

 fed upon mealworms exclusively produced a dirty pink after the first moult, 

 others which received in addition to the ordinary soft bill food minced raw beef 

 became almost white, which shows that the mealworms fed on dry vegetable 

 matter like bran will not produce the natural scarlet in the feathers. During my 

 experiments with the Sanguineous Iloney-eater (Blood-bird) I allowed some of 

 these to fly in a large outdoor aviary set with grape-vines and other plants, 

 which attracted myriads of the tiny leaf-fly. The flies served the Blood-birds as 

 food in addition to the sugar water they received. All these birds moulted per- 

 fectly into their natural scarlet plumage. At the same time others were placed 

 in a large cage with plenty of sunlight, and fed on sugar water sprinkled only 

 with dried and crushed cocoons of flies and with powdered flies. The birds did 

 very well on this diet and moulted without trouble but — a washed-out pink ! This 

 seems to prove that it was the leaf -fly iu conjunction with unlimited sunlight 

 which caused the natural colour to reappear. 



It is a remarkable fact that even in nature these colour changes always 

 affecting the red pigment may take place unconditioned by age. I have seen in 

 Fiji numbers of yellow headed Parrot Finches flying with flocks of red headed 

 ones, the true colour of the species. I have had young ones of this species which 

 eventually moulted out yellow headed, neiiher is it an uncommon tiling to see 

 yellow or copper headed Gouldians — the offspring of either black or redheaded 

 ones ; and I may state here that I received for several years running a silver 

 white Oralah, whose brothers and sisters out of the same nest were naturally 

 coloured. I think I am safe in saying that it is only the scarlet which undergoes 

 these variations, but where the actual cause lies is still a mystery to me beyond 

 what I know of experiments. The common Blue Wren for instance, which breeds 

 freely in my aviary, has always produced young which colour out according to 

 nature, whereas the young of the Scarlet Backed Wren only show the dirty 

 orange like the parent after the first moult. Now the young of the Scarlet 

 Breasted or Red Capped Robins have never even moulted out a semblance of their 

 natural bright scarlet. 



During my experiments in artificially eliminating colour from feathers, I 

 found that, it can be done by a wash in chlor-ether, or chloroform. Removing 

 some breast feathers from a Scarlet Breasted Robin, I found the new feathers 

 formed a patch of dirty white amongst the still perfect original scarlet breast 

 feathers, this seems to show conclusively that I had not been able to supply the 

 necessary food for the production of the red colour pigment, and that the deposit 

 of colour pigment in the old original scarlet feathers was not influenced or inter- 

 fered with by food changes, for the simple reason that the old feather was not 

 subject to matter changes in the body. In Parrots the colour changes are not 

 nearly so frequent or so severe, the probability being that their nature better 

 adapts itself to the food and life of captivity. If one begins to wonder how 

 pigment has gradually been modified for the development of colour in nature 

 one is lost almost as hopelessly as when one attempts to comprehend infinity or 

 space. 



