240 THE MYOLOGY OF THE RAVEN. 



this vinculum as I found it to be present in the Ground 

 Cuckoo. 



"In order to show how different this disposition of these 

 plantar tendons may be, I quote Garrod's description of 

 his dissection of the foot of a specimen of Megalcema 

 asiatica (Fig. 65 ter.}. He says, in this bird ' the two 

 tendons descend behind the ankle as usual, having their 

 origins typical. ' There is nothing peculiar till they have 

 descended two-thirds down the tarso-metatarse. About 

 opposite the middle of that bone the flexor longus 

 hallucis sends a vinculum downwards as in the Fowl, to 

 join the tendon of the flexor perforans digitorum. Just 

 above the metatarso-phalangeal articulation the tendons 

 become arranged for distribution in a most uncommon 

 manner. The tendon of the flexor perforans digitorum 

 does not split up, but runs to one digit only namely, 

 the third toe, which is the outer of the two that are 

 directed forward. It is covered superficially by the 

 flexor perforans digitorum, just as that latter muscle is 

 splitting up to be distributed to the hallux as well as to 

 digits 2 and 4. In these birds we have, therefore, the 

 flexor longus hallucis arising from the lower surface 

 of the femur only, running through the ankle at 

 the outer side of the other deep tendon, and sending 

 a vinculum downwards all of which are special cha- 

 racters of that muscle only, it being distributed to 

 three toes, whilst the flexor perforans digitorum only 

 supplies one.' 



" In Fig. 65 quin. the arrangement in the Apteryx is 

 well shown, where the vinculum is so large as compared 

 with this band in the Fowl, that it almost appears upon 

 sight that the two flexor tendons are fused into one 

 common one, at the point of union. 



"A close study of this arrangement, however, will throw 



