146 ANNALS OF SCOTTISH NATURAL HISTORY 



unknown and unsuspected breeding-place in our northern 

 islands, though where such a place should be I could not 

 suggest. 1 This pretty fancy has, of course, been quite 

 dispelled by the abundant evidence that they are not in 

 breeding condition ; 2 but some compensation is afforded 

 by the interesting fact, now conclusively established, that 

 members of a group like the Tubinares, which contains some 

 of the birds best endowed with the power of flight, should 

 so moult their wings as to become almost, if not quite, 

 incapable of it, and I trust the matter will receive due 

 attention from those who have the opportunity of further 

 investigating it. From very ancient times it has been 

 known that the Anatidce become flightless by the simul- 

 taneous shedding of their quills after the breeding season, 

 and quite recently the same thing has been shown by Mr. 

 Bonhote and others to occur in other groups, as the Rallidce 

 and Colymbidce, but we could hardly have suspected such 

 rovers of the sea as the Procellariidce to be subject to a 

 disability of the like kind. 



I have compared the two specimens obtained off St. 

 Kilda in the fourth week of July 1899 with two in the 

 Strickland Collection (No. 3075 a and //) in our Museum 

 that are apparently full winged, and the condition of the 

 former may thus be briefly described : 



A. Wings all the primaries new, the first from the outside not 

 exceeding one-third of the full growth ; 



second from the outside longer than the preced- 

 ing, but shorter than the next ; 

 third from the outside, though the longest in the 

 wing, reaching only the proximal part of the 

 whitish patch on the upper tail-coverts ; 

 fourth and fifth, more advanced in proportion, but 

 hardly full grown. 



Tail two middle rectrices new and about half grown, the 

 outer pair also new, but all the rest old. 



1 I cannot help here acknowledging the superior intelligence of Faber, who 

 (nt supra, col. 7^6) so long ago rightly divined that the breeding-place of this 

 species lay to the southward of that of the Manx Shearwater. 



2 See also Dr. Gadow's testimony, cited by Messrs. Harvie-Brown and 

 Barrington (/// supra, p. 74), in regard to the specimen shot at Rockall. 



