252 THE ZOOLOGIST. 



Not only does this index afford a means for a comparison of 

 the specimens, but it should have the advantage also of giving a 

 more accurate estimate of the real flight-feather area. 



Table I. has been compiled from the indices thus obtained by 

 placing them side by side, according to the respective sex and 

 approximate age of the specimens, and in serial order of 

 diminishing figures of these indices. 



On the whole, the result of this investigation for eliciting 

 additional evidence in proof of the establishment of a clearly 

 defined line between males and females from the point of differ- 

 ence in the length of the flight-feathers cannot be said to have 

 been a very satisfactory one — at any rate, not for this particular 

 species. The same may very reasonably be inferred from the 

 genus as a whole, to which this species belongs. 



On the other hand, and which Table I. shows also, it has been 

 productive of supplying an approximate estimation of the rates 

 of percentages at which the two sexes participate in the maxima 

 and the minima of excess or reduction respectively. Thus 

 18*5 per cent., or five males only, absolutely exceed in greatest 

 length of flight-feathers; the 59*3 per cent.=nineteen individuals, 

 indiscriminately represent males and females, as well as every 

 range of length ; these are Nos. 6 to 21 of Table I., or consider- 

 ably over the half of this large series of birds. Of females, six 

 only are absolutely inferior in length, forming 22*2 per cent, of 

 the whole. By dealing, however, separately with the sexes, the 

 five males just referred to, out of a total of sixteen, with abso- 

 lutely higher indices, form 31*2 per cent. Similarly, of the 

 eleven individuals constituting the female portion, six of them 

 show indices absolutely inferior to the remaining seven, or 

 54*5 per cent., a little over the half for females.* 



The measurements obtained for the seventh or longest pri- 

 mary, when compared with the indices derived from the aggre- 

 gates of all the flight-feathers in the wing, do not coincide always 



* These birds are a non-migratory species, and the greater proportion of 

 males to females in a collection made in the same locality as this one was, 

 may be taken as a fair estimate for the proportion of the sexes in a free 

 state. This probably accounts also for the great number of them existing still, 

 although they were considerably disturbed by the influx of the white popula- 

 tion settling everywhere in the country. 



