THE 



MONTHLY MICROSCOPICAL JOURNAL. 



FEBRUARY 1, 1873. 



I. — On the Development of the Skull in the Tit and Sparroiv- 

 Eawk By W. K. Parkee, F.R.S. 

 (Bead lefore the Royal Microscopical Society, Dec. 4, 1872.) 



Part II. 



Plates V. and VI. 



My next instance of cranio-facial growth is the representative 

 of quite another " Family," or rather " Order " of Birds ; this is the 

 Sparrow-Hawk (Nisiis vulgaris), a good type of a huge group which 

 begins, in extant forms, with the Cariama (Dicholophus), and culmi- 

 nates in the Falcon and Eagle. 



My illustrations are of a half-fledged nestling of this robber, " a 

 speckled bird among the birds of the forest," the dreaded enemy of 

 the Warbler tribe. 



This kind of bird, in this its immature state, is excellent for 

 comparison with the Reptile's skull, especially that of the Turtles 

 and Tortoises ("Chelonia "). It would seem at first sight that the 

 frowning brow and the arched and knife-edged beak were special 

 modifications of this form of bird, in thorough harmony with its 

 character and its habits, and having no other or wider meaning. 



But the permanent down-bend of the beak and the bony roof to 

 the brow are both retentions of the Chelonian type of structure, 

 not derived from the Turtle, and yet pointing to a probably common 

 origin for both. Yet with all these evident reptilian marks upon 

 them, in many respects these birds are to their own class what 

 Tigers and Lions are to the Mammalia, namely, amongst the most 



EXPLANATION OF PLATES V. AND VI. 



Plate V., Fig. 1. — Skull of Nestling Sparrow-Hawk (Nisus vulgaris) (side 

 view), x 2. 

 „ „ 2. — Ditto, ditto (lower view), X 2. 



„ „ 3. — Ditto, ditto (upper view), x 2. 



„ „ 4.— Part of Fig. 2, x 3. 



Plate VI., „ 1.— Skull of same (end view), x 2. 



„ „ 2.— Fore-view of skull, with face cut away, x 3. 



„ ,, 3. — Part of palate of ditto, x 3. 



i, „ 4. — Os hyoides of same, x 2. 



VOL. IX. H 



