'the retrospect, '^9 



chiefly consisting in difference in size and colour. Macgillivray, for Instance, 

 says differences as to size between individuals, even of the same sex^ are 

 such that many persons have supposed the Sparrow Hawk divisible into 

 several species. Males, he says, vary an inch and a half, and females as 

 much as three inches; and he adds that "the Scutellae are pretty regular 

 as to number in this species." 



Now, on the first, second, third, and fourth toes, the Hawk I possess 

 numbers, respectively, eight, ten, twenty- two, thirteen, scutellae; whereas 

 the Sparrow Hawk numbers nine, fourteen, twenty -eight, and eighteen. 

 Surely that acute observer of Kature never could have applied pretty regular 

 to this marked discrepancy. 



In the unknown Hawk the tarsi are an inch and three eighths, whereas 

 the tarsi of the Sparrow Hawk (male) are two inches and one-eighth, and 

 of the female, two inches and five-eighths. The claws in the unknown 

 Hawk are a pale horny white, with scarcely any incurvation, and not half 

 the length of the claws of the Sparrow Hawk, which are, according to 

 Selby, "long, strong, black, and hooked." According to Yarrell, "curved, 

 sharp, and black." According to Morris, black, pale bluish at the base." 

 According to Bewick, "black." According to Jardine, "sharp and hooked." 



This difference as regards the claws in colour, length, and form, seems 

 to be extreme in merely a variety. 



The length of tail in the unknown Hawk is five inches; in the male 

 Sparrow Hawk it is six inches, in the female seven inches and a quarter. 

 The outer tail feathers in the unknown Hawk are an inch shorter than 

 the eight central ones, whilst in both the male and female Sparrow Hawk 

 they are not more than one-sixteenth of an inch shorter. The second 

 outer feathers in the unknown Hawk are half an inch shorter than the 

 eight central ones, whilst in the male and female Sparrow Hawk they are 

 equal. This difference in the tail seems to me to be too wide to be merely 

 accidental. In the unknown Hawk the length of the tail extends an inch 

 beyond the tip of the wing, whereas the tail in both male and female of 

 the Sparrow Hawk extends three inches beyond the tip of the wings. 



In the unknown Hawk the length from the anterior bend of the wing 

 to its tip is seven inches and three-quarters; whilst In the male Spar- 

 row Hawk it Is seven inches and five-eighths, and in the female nine 

 Inches. The longest feather In the wing of the unknown Hawk is the 

 third, whereas in the Sparrow Hawk the longest feathers are the fourth 

 and fifth. In the unknown Hawk the second longest feather In the wing 

 Is the second quill, whilst the second longest in the Sparrow Hawk is the 

 third quill. The third longest feather in the unknown Hawk Is the outer- 

 most quill, whilst the third longest in the Sparrow Hawk Is the second 

 feather In the wing. 



