O GREY REDSTART. 



tlie 9tli. and lOtli. of April, and in the number he did 

 not see a single TitJiys. The arrivals of Tithys, which 

 do not winter in the country, are always eight days 

 later." 



It is impossible, I think, to resist the force of these 

 remarks. If not a species, S. Carii is at least a per- 

 manent variety or race of a very interesting character, 

 and quite as much entitled to specific distinction as the 

 Shrikes described in a former number. 



In estimating the value of colour as an element in 

 determination of species, it cannot be too generally 

 kno^vn that many of our most beautiful birds, such as 

 the splendid Humming Birds, have in reality no colour 

 at all, so far as this depends upon the deposit of pig- 

 ment. The effect of colour is entirely produced on 

 many feathers by delicate striae, which decompose the 

 light, the feather itself being colourless. This therefore 

 is a permmient organic change in the structure of the 

 bird, and not dependent upon those causes which 

 influence the deposit of pigment. Colour then must 

 be considered a valuable test of specific distinction 

 when permanent. In the present instance, that of S. 

 Carii, the peculiarity appears to be in the incapability 

 of producing breeding plumage feathers. This is prop- 

 agated from one to another, like many other abnormal 

 peculiarities in all classes of animals, and the result is 

 a permanent variety or race, which the sagacity of 

 Temminck and others led them to indicate as distinct 

 from specific difference. 



The Sylvia Carii, or, as I have taken the liberty of 

 calling it, the Grey Redstart, inhabits the top of the 

 Basses-Alpes, where it breeds in old isolated chalets or 

 hilts. "It lays two sets of eggs, one at the end of 

 April in more temperate regions, when the high moun- 



