SOME RESULTS OF OSTRICH INVESTIGATIONS. 283 



reptilian ancestry compared with birds generally, a relationship 

 supported by the presence of the claw on the first and second 

 digits of the wing, and the occasional distinctness of the third 

 digit, with its two phalanges. 



Specific Distinctness of Northern and Southern 



Ostriches. 



Whether the northern and the southern ostrich are to be 

 regarded as separate species, or only as sub-species or varieties of 

 a single species, raises the ever-recurring, but unanswerable, ques- 

 tion as to what constitutes a species. In the foregoing we have avail- 

 able all the data which the systematist could possibly desire to 

 enable him to reach a decision. A germinal character, baldness, 

 occurs in one, but is wanting in the other, while the dimensions 

 and colours of the body, as well as certain features of the egg 

 are also distinctive and germinal. The characters are retained 

 when the members of one race are subjected to the same environ- 

 mental conditions as the other, showing they are not dependent 

 upon external circumstances. They can alL be regarded as distinct 

 elementary characters in the De Vriesian sense, and the combina- 

 tions might be held to warrant us in regarding the two as 

 specifically distinct. 



On the other hand, the birds are proved to interbreed freely, 

 and the offspring are fertile, both inter se and with the parental 

 forms. The fact that similar degenerative processes — ^loss of 

 ])lumage, scales and claws — are proceeding in both also points to 

 a close germinal relationship. In the opinion of many systematists 

 the physiological fact of fertility alone would be deemed to 

 justify specific unity. 



The ostrich ranges over all the habitable parts of Africa, and 

 there is every likelihood that in intermediate areas between north 

 and south a mingling of the two races goes on, producing a mixed 

 population, composed of all possible combinations of the two sets 

 of characters. Thus in the East African ostrich, .S". uiassaictts, as 

 the writer has found in visiting the ostrich farms jn British East 

 Africa, the colour of the hen and immature cock is a cream 

 yellow, while the mature cock has the head, neck, and legs 

 scarlet, and the birds are somewhat larger than the southern. 

 The bald patch is present, and the eggs are pitted. The Somali 

 ostrich, S. molybdo phones, is described as a smaller, darker bird 

 than the southern, but the bald patch is wanting, and the coloura- 

 tion is like that of the southern, and the eggs are pitted. 



If the entire ostrich population of xA.frica were gathered 

 together, we are probably justified in thinking that all intermediate 

 forms would be forthcoming between typical northern and 

 southern birds. An exception would occur, however, in the case 

 of the bald patch, for. however much intercrossing had taken 

 place, the character would never be intermediate, but 

 would be wholly present or absent ; and though the 

 dimensions, colours, and q^^ characters appeared in varv- 



