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Decjeneratioii in the Ostrich 



Here, as in Table I, we have variation as regards the number of 

 plumes grown by each chick, probably indicating lack of germinal 

 purity in the parents for the most part ; and we have also variations of 

 one or two plumes as between the two wings of the individual, pointing 

 to a lack of factorial stability in connection with the one or two end 

 plumes, and perhaps also influencing the individual variation resulting 

 from the mixed ancestry. 



TABLE III. 

 Bfeeders : 



In Table III both the cock and hen represent the lowest plumage 

 numbers available among the breeding birds, and were selected to 

 determine how far the low numbers would breed true; also if it 

 would be possible to reduce the plumes beyond the minimum yet 

 known, namely, 33. It must be admitted that the ten chicks show a 

 remarkable uniformity considering the mixed parentage, the extreme 

 variations, 33 to 36, representing a difference of only three plumes, while 

 in the second series the difference, 35 to 39, is four, and in the first 

 series, 39 to 44, as many as frve. Many of the chicks show vestigial 

 feathers at the elbow end of the row of remiges and those of the coverts, 

 while in one as many as four under-coverts are absent from the distal 

 end of the row, a most unusual number. 



If the terminal remiges are in a more or less degenerative phase in 

 all ostriches, as is here maintained, we may expect that retrogression 

 will be hastened by breeding together ostriches in which the change is 

 most in evidence. Any loss achieved in this way would be most mani- 

 fest in birds producing the minimum number of plumes, as the present 

 limit of variation would be still further lowered. By selecting the 

 lowest numbered birds available it should be possible still further to 

 reduce the number, particularly if in-breeding were carried out. It 

 would naturally constitute direct experimental evidence of degeneration 

 and the influence of selection if such a reduction could be effected. It 



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