292 MR. H. SCHERREN ON [ Apr. 21, 
April 21, 1903. 
Dr. Henry Woopwarp, F.R.S., Vice-President, 
in the Chair. 
The Secretary read the following report on the additions made 
to the Society’s Menagerie in March 1903 :-— 
The registered additions to the Society’s Menagerie during the 
month of March were 67 in number. Of these 14 were acquired 
by presentation, 43 were received on deposit, and 10 in exchange. 
The total number of departures during the same period, by death 
and removals, was 89. 
The following papers were read :-— 
1. Linnzeus and Hunter on Feather-Tracts. 
By Henry Scuzrren, F.Z.S. 
[Received March 12, 1903. } 
(Text-figure 49.) 
The credit of using the feather-tracts of birds as a means of 
classification belongs undoubtedly to Nitzsch, whose results, edited 
after his death, by Burmeister, were published at Halle in 1840 
under the title ‘ Pterylographie’. An English edition, translated 
by W.S. Dallas and edited by Dr. Sclater, was brought out by 
the Ray Society in 1867. Pterylosis, or the distribution of these 
feather-tracts, is, according to Prof. Newton, “of prime taxonomic 
importance in Ornithology, though more in the investigation of 
small than of large groups.” This also seems to have been the 
opinion of Nitzsch himself, who, however, was not aware that 
anything at all had been done even in noting the existence of 
such tracts and of the featherless spaces which he called apteria. 
In his Introduction he says :— 
T may, therefore, flatter myself with the hope of awakening the interest 
of naturalists by the announcement of my new results, and, by the enumera- 
tion and detailed description of the feathered regions of the bodies of birds 
to which I give the name of feather-tracts (pteryle, Federnfluren), of 
proving that these, new and surprising as they may appear to many on the 
first glance at my figures, really furnish equally significant and important 
characters for the certain and natural discrimination of the families of 
birds. 
Professor Newton (‘ Dict. Birds,’ Introd. p. 63, note 1) says that 
the only men before Nitzsch’s time who seem to have noticed 
feather-tracts were the great John Hunter and the accurate 
