J. K. DrKRDKN 17 



The avonij(o number of plunu's on tin- South AlVican ostrirh is 

 therefore the same a.s that on the North African, an important con- 

 clusion which could not have been arrived at without the opjxjrtunity 

 of counting hirge numbers of each. 



As the northern ostriches now at (irootfontein were all procund 

 originally by the Arabs of Nigeria as chicks from wild nests, and are 

 uninfluenced by any artificial breeding, we may presume that their 

 plumes repR\sent the avemge for the North African wild bird, and we 

 have therefore go<xl reason for concluding that the ostriches over tht; 

 whole continent of Africa pnMluco the .same average number. From 

 this it follows that during the fifty years of ostrich farming in South 

 Africa no advance ha^ been made on the number of plumes originally 

 present on the wild bird. On the average the domesticated birds of 

 to-day produce the same quantity of plumes as the original birds with 

 which the first ostrich farmers commenced in the sixties. 



Though somewhat remarkable at first sight this result is scarcely to 

 be wondered at if we bear in mind the principles underlying ostrich 

 breeding : Farmers have bred for quality ; quantity has never been taken 

 into account. Great advances have been made in the so-called quality 

 characters of the individual plume, but in doing this no attention has 

 been given to the number of feathers which one bird produces as com- 

 pared with another, and therefore no numerical change hiis taken place. 

 It is a good instance of the principle that no progress is ever made as 

 a result of indiscriminate breeding, unless a character has some selection 

 value, or mutations are taking place. 



Cross-bred Ostriclies. Seeing that the northern and southern birds 

 have the Siime average number of plumes and are a mixture of hetero- 

 zygotes, no change is to be expected in the number of plumes on cross- 

 bred chicks compared with what would be procured by mating two 

 northern <jr two southern birds. The table given below is an example 

 of the results which have been obtained. The arithmetical mean of the 

 parents is 36*24 and of the chicks 3028, but for a larger series the 

 average is 36'31 which agrees more closely with that of the two race.s. 



