A CENSUS OF GLASGOW ROOKERIES. 21 



known, from that on Lochfyneside have been preserved, but an 

 examination of the fronds from Corrie in the Herbarium of the 

 late Mr. Combe, or those from Dougarie in that of Mr. Kidston, 

 leave no room for doubt as to their character as those of wild 

 plants. As it has thus been found on the North-east side, on 

 the West side, and at the North end of Arran, at different 

 dates and by different discoverers, and some miles up Lochfyne- 

 side, by yet other botanists, I think it is satisfactorily established 

 that Trichomanes radicans, Sw., is a native of Scotland, and 

 that we are justified in placing it on our list. 



A Census of Glasgow Rookeries. 



By Hugh Boyd Watt. 



[Read 29th May, 1900.] 



A CENSUS of British Birds is one of the tasks which lie before 

 our Ornithologists, and one which can be readily overtaken by 

 the exercise, in a systematic manner, of attention, care, and 

 patience. The numbers of some breeding species, such as the 

 Bearded Titmouse, the Golden and Sea Eagles and other 

 Accipitrine birds, the Gannet, the Heron, the Great Skua, and 

 the game birds, are already approximately known; and as regards 

 other species, and amongst them some of our commonest birds, 

 each nesting season brings round an opportunity of enumerating 

 them with fair accuracy. Constant controversy prevails as to 

 increase or decrease in the numbers of our birds and the 

 utility of protecting certain species, and a census made on one 

 system over a series of years would furnish material for deter- 

 mining some disputed points. The Rook (Corvus frugilegus, 

 Linn.) — one of our most common birds, with no concealment or 

 seclusion in its nesting habits, and not shunning observation — is a 

 species of which an example might be made, and this brief paper 

 gives the results of an enumeration made this season of the 



