TO BIRD-ANATOMY AND CLASSIFICATION. 



199 



Fig. 6. 



Fig. 7. 



Ibis, 1881, 

 p. 13. 



A typical Passerine foot Foot of Gallus banfciva 



(from P. Z. S. 1875, p. 347, fig. 9). (from P. Z. S. 1875, p. 341, fig. 1). 

 V, Vinculum. 



tendinous slip to the hallux comes off from the blended tendon, IMs,'1881, 

 apparently springing from the inner side. A slight modification of this 

 produces an arrangement by which the hallucial slip seems to come off 

 from the inner side of the flexor perforans tendon in its upper part, 

 before it has been joined by the flexor hallucis. This last-named con- 

 dition obtains in such birds as Momotus, Merops, and Dacelo. 



"When the hallux is absent, as well as in Struthio (where only two 

 digits are present), the two tendons fuse completely in the leg, and the 

 compound tendon is distributed in the usual way to the three (or two) 

 digits. In many birds with a hallux, when there is no long flexor to 

 that digit, the slip to it is extremely small ; and in some cases it is alto- 

 gether absent. 



In the Trogonidse, as might have been expected from the well-known 

 peculiarity of their feet, an equally peculiar arrangement of the plantar 

 tendons obtains (L c. p. 345, fig. 6). 



By far the most interesting feature, however, brought out by Prof. 

 Garrod's investigations into this subject, is the discovery of the existence 



