26o SOME RESULTS OF OSTRICH INVESTIGATIONS. 



for on recovering from an injury to the neck or body it is often 

 found that the scar of the new skin shoiws a reddish tinge. 



Cross-bred Ostriches. — The colour of the skin of cross-bred 

 chicks is intermediate between that of northern and southern 

 chicks. The legs, body and large scales are a pale yellow, which 

 is lighter than that of Cape chicks, but never so deep as that of 

 Nigerian chicks. The adult cross-bred hen retains the light 

 yellow body colour, though usually it becomes a little darker com- 

 pared with the chick. The colour remains darker than that of 

 the pure northern hen, but is invariably lighter than the pure Cape. 



The cross-bred cock retains the uniform light yellow of the 

 hen until sexual maturity approaches. He then assumes a pink 

 tinge in places, and later the bright scarlet. As noted, however, 

 it is in the extent of the red colouration, not in its intensity, that 

 the northern and southern cocks differ so conspicuously ; in the 

 former it is diffused practically all over, while in the latter it is 

 limited to the head and legs below the ankle joint. The sexually 

 mature cross-bred cock is decidedly intermediate between these 

 tv^o as regards the area of the body assuming the red colour. The 

 head and tarsus are scarlet as in both parents, but a slight pink 

 colour appears on the upper part of the leg and also over the 

 neck, and may even tinge the other parts of the body, though 

 without approaching the bright red oif the norhern parent. The 

 various cross-bred cocks naturally differ as regards the degree 

 and extent of the colouration, but they never wholly follow one 

 ])arent or the other. In extreme cases the body colour may be 

 a grey blue almost like the southern cock or a grey yellow nearly 

 like the northern, but all kinds of intermediate tints are to be met 

 with, even in birds from the same nest. 



As regards the two F2 chicks, the colour of the body, legs and 

 neck is quite as dark as that of any Cape hen, showing no in- 

 fluence from the lighter colour of the northern grandparent and 

 the intermediate light colour of the cross-bred parents. Both 

 being hens, however, the colour is not so distinctive as it would 

 be in the case of cocks. Taken as a preliminary result, it cer- 

 tainly suggests that the colours of the northern and southern 

 birds have a separate factorial basis, and that segregation will 

 take place in the second cross-bred generation. The rearing of 

 further F2 chicks will be awaited with interest as likely to solve 

 the problem. 



Bald Head Patch. 



The crown of the head of the .South African ostrich is covered 

 with short, hair-like feathers, which often form a longer tuft in 

 the middle. A bald pineal spot, present in all ostriches at the back 

 of the head, is so small in the adult as to be only noticeable when 

 the feathers are turned aside. The North z-\frican ostrich, on 

 the other hand, is distinguished by having the top o\ the head 

 for the most part naked, a bald patch beginning at the back and 

 extending forwards in a shield-like faf;hion between the e\'es. 



