SOME RESULTS OF OSTKUll INVESTIGATIONS. 255 



southem bird. (PI. 4A.) The average long diameter is 6.15 

 inches, the short diameter 5.35 inches, and the weight 3 lbs. 1 1 07. 

 Found in Northern and Western Africa, and in times past 

 ranged eastwards to Abyssinia, Arabia, and South Palestine. 



B. — The South African Ostrich, Struthio australis, Gi<niey. 

 — Smaller than the North African, the less size being due to the 

 slender and shorter legs and neck rather than tO any difterence in 

 the size of the body. The head extends about 7>4 ft. from the 

 ground, the length from the tip of the beak to the end of the 

 tail is 73^ feet, and the total weight about 240 lbs. The neck i.s 

 about 3 ft. long, and the body feathers pass upwards for about 

 I ft. ; the knee joint is about 3j/'2 ft. from the ground ; a claw is 

 rarely present on the small toe, and the scales on the tarsus and 

 third toe are usually continuous. 



The wing plumes average about 36 to each wing, but vary 

 from 33 to 42. 



The skin of the neck, body, and legs is pale yellow in chicks, 

 and dark grey in the mature hen, and dark blue in the cock. In 

 the sexually ripe cock only the beak, front part of the head, 

 naked skin around the eyes, and tarsal scales are bright scarlet, 

 and the rest of the tarsus and toes pink, but the redness does not 

 extend above the ankle. 



The crown of the head is without any bald patch, and often 

 bears a tuft of longer, hair-like feathers in the middle. 



The egg is deeply pitted all over, smaller and more oval than 

 in the northern bird. (PI. 4A.) The average long diameter is 

 6 inches and the short diameter 5 inches ; the weight about 33/2 lbs. 



Inhabits practically the whole of the sub-continent of South 

 Africa. 



Observed alongside one another, as can now be done at 

 Grootfontein, no one could fail to distinguish the northern from 

 the southern ostrich. The greater height of the former, the stronger 

 limbs and light yellow colour of the skin are obvious features, 

 while the sexually mature cock is still more distinctive on account 

 of the brilliant scarlet of the head, neck, and legs, and the red 

 colour of the body generally. The naked patch on the head, and 

 the smooth, larger eggs are just as constant distinguishing 

 features. Many small dififerences of feather structure also occur, 

 and are of much importance to the practical ostrich farmer. 

 Hitherto all the distinguishing characters of the imported northern 

 ostrich have been retained under the new conditions of South 

 Africa, and re-appear in the progeny, showing that they are 

 germinal and independent of climatic and other environmental 

 influences. 



Whether the northern and the southern ostrich are to be 

 regarded as distinct species depends largely upon one's concep- 

 tion of the term " species," and will be discussed later. It may be 

 noted, however, that the two are found to interbreed freely and 

 reciprocally, and the crosses or hybrids have also been proved to 

 be fertile, both inter se and with either of the parent forms ; at 



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