SOME RESULTS OF OSTRICH INVESTIGATIOXS. 269 



Tauli-: 7. — Number of First-roiv Pinnies on Cross-bred Cliieks 

 from mating a North African Cock with a Soitth African 

 Hen. 



Parents. Right Wing. Left Wing. 



N.A. Cock. No. 78 37 36 



S.A. Hen, No. 225 36 36 



Chicks. 



1. No. 300 36 36 



2. No. 301 35 36 



3- No. 315 3^"^ ^7 



4- No. 316 36 Z7 



5. No. 318 :^7 36 



6. No. 320 35 36 



7. No. 321 36 36 



8. No. 322 36 35 



9- No. 323 38 37 



A 42-PLUMED Ostrich. 



Among the Ca])e birds in the Grootfontein flock two have 

 been disc(^vered with 42 phmies to the first row, though the rest 

 have the usual average of about 36. Of the two original birds 

 one has since met v/ith an accident and died. The birds were 

 procured several years ago from two farmers widely apart, 

 without any suspicion of their high number of plumes. It is 

 noteworthy that though search has since been made among the 

 same flocks, yet in neither case has another 42-plumed bird been 

 found. At first it seemed as if two distinct strains of ostriches 

 were represented in South Africa, as compared with the single 

 strain in North Africa, one with approximately 36 plumes as 

 the average, and another with 42. The countings on farmers' 

 birds have, however, given no support for this view ; they have 

 disclosed no individual bird exceeding 40 plumes, nor any influence 

 from a 42-plumed strain. Hence it is concluded that the occur- 

 rence of ostriches with 42 plumes is altogether exceptional among 

 Cape birds, and has has had no recent influence on the general 

 average. Likewise none of the Nigerian birds has more than 39 

 plumes, nor any of the chicks reared from them ; so the influence 

 of a 42-plumed strain is non-existent in North Africa. 



As regards their origin, it is manifest that the 42-plumed 

 birds represent a distinct departure from the ordinary 36-plumed 

 birds. Were no other evidence available, the high number might 

 be looked upon as a meristic mutation, and the birds give progeny 

 with such high numbers as to show that the extra plumes are not 

 merely the extreme limit of a fluctuating series, but are of 

 factorial value. They have also been considered in the light of 

 reversions to any earlier ancestry, but full consideration leads us 

 to account for them otherwise. Recent observations, to be given 

 in the next section, have shown that the ostrich presents us with 

 numerous stages, indicating the course of the degeneration which 



