56 Mr, J. Hewitt on a Three-toed Ostricli Cinch. 



in the Ostrich embryo (see Broom in Trans. S. A. Phil. 

 Soc. XYi, pi. ix), but if such be the correct explanation the 

 presence o£ 3 phalanges is very remarkable, for the hallux 

 of birds and other sauropsida in general has only 2 pha- 

 langes. I do not, therfore, consider it as a hallux, and in 

 view of the fact that this additional digit is altogether out of 

 place in the system of symmetry of the limb whilst on the 

 other hand it more or less balances the third toe about 

 the reduced second, it seems best to regard it not as atavistic 



Left foot from below. 



but merely as a meristic variation. According to Mr. 

 Bateson {' Materials for the study of Variation ') when 

 dealing with some instances of 5-toed fowls in which the 

 additional digit is likewise on the inside of the foot, the 

 most usual arrangement has the digital formula 3.2.3.4.5 

 (instead of 2 . 3 . 4 . 5 in normal fowls) ; this seems to me a 

 fairly parallel case to the one under consideration, although 

 the fowPs additional toe does not connect directly with the 

 tibio-tarsus as in the Ostrich chick. The cliick only lived 

 about a fortnight and was very clumsy in its movements, 

 being unable to stand ; it was presented to the Albany 

 Museum bv Mr. Dold of Grahamstown. 



