27^ 



SOME RESULTS OF OSTRICH INVESTIGATIONS. 



considerable support for the idea that degeneration is also in 

 process even here, so that ultimately all the toes may disappear, 

 if the bird survive the intervening stages. 



Along the front of the tarsus extends a series of large, nearly 

 rectangular scales, which in most cases passes uninterruptedly 

 to the end of the big toe. (Fig. 3.) Over the leg their contiguous 

 edges simply meet, but they are imbricated where the tarsus 

 joins the toe, and also over the latter, thus allowing for the 

 bending movements during walking and running. Along the 

 tarsus the scales retain approximately the same size, but at the 

 junction with the toe they usually become somewhat smaller, 

 enlarging again distally. Occasioally a distinct break in the 

 continuity occurs at the joint, several of the large ones disap- 

 pearing and being replaced by the insignificant scales which 

 cover the surface of the limb generally ; and in rare cases a 

 second break in the continuity takes place over the joint about 

 the middle of the toe, thus giving a proximal and a distal series 

 of digital scales. 



The number of scales fluctuates in different individuals, and 

 also on one limb as compared with the other, and occasionally 

 irregularities are introduced owing to single scales being partly 

 subdivided. At the breaks the large scales tend to pass insensibly 

 into the small one of the limb, hence any enumeration is only 

 approximate. Actual counting give the following: — 



Table 9. — Number of Scales in Tarso-pedal Scutellation. 



A . — Con fin u o us- 



Right Tarsus 

 and Toe. 



I. 

 2. 



3- 

 4- 



53 



55 

 57 

 58 



Left Tarsus 

 and Toe. 



55 

 53 

 56 



57 



B. — With one break- 



Tarsus. Toe. 

 16 

 17 



27 



2^ 



Tarsus. Toe. 



27 

 30 



17 

 19 



C. — H'itli t-cco breaks — 

 Tarsus. 



Toe. 



Tarsus. Toe. 



I. ... 29 58 29 58 



2- ... 30 59 31 69 



3- • • • 32 69 31 711 



The break in the continuity occurs rather rarely, especially 

 in southern ostriches. Out of 20 Cape birds of mixed breeding, 

 only one showed an interruption, while in 20 mixed Nigerian 



