The Scottish Naturalist. 13^ 



of the employment of several words as practically equivalent. The 

 existence of defects in method must have been perceived by many a 

 biologist, the first step to provide a remedy is to obtain a clear 

 view of the evils, and not only has Mr. Davidson given us this, 

 but he has also indicated how to overcome them. We heartily 

 commend the Logic of Definition to the careful study of all from 

 whom we hope for further advance in the fields of science, assured 

 that they will find their reward in its study, and will agree with us 

 that a debt of gratitude from botanists and zoologists alike is due 

 to its author. 



SCOTTISH SCIENTIFIC SOCIETIES. 



ABERDEEN NATURAL HISTORY SOCIETY, Nov. ig, 

 1884. — Annual Meeting. — The reports indicated that the Society is doing useful 

 work. In the session 1883-84 there were six meetings, and during the summer 

 two excursions were made, viz., in June to Braes of Gight on the River Ythan, 

 and in July to the Loch of Park, about 12 miles from Aberdeen. The object of 

 the latter excursion was to investigate the plants growing in the loch. It was 

 found that the greater part of it does not exceed three feet in depth of water. 

 The shallows are densely overgrown with Myriophyllum alternifloritm, 

 Lobelia Dortmanna, Alisma Plantago; and several of the taller Monocotyledons, 

 such as Typha latifolia, Scirpus lacuslris, &c, are plentiful around its swampy 

 shores, but it proved poor in Polamogetons, and in the other water-plants that 

 occur in the East Perthshire lochs so plentifully. Juncus Balticus formerly 

 grew beside the water,, but a search failed to detect it there last summer. 



December $th. The President, Prof. James W. H. Trail, gave an account 

 of a visit to Canada and the N.E. States, in August and September, in connec- 

 tion with the meeting of the British Association in Montreal, to which he had 

 been commissioned as delegate from the Society. Mr. Alexander Murray 

 thereafter read some observations On a Larva that Burrows in the 



Leaves of the Common Sunflower, with special reference to the 



means of defence against the visits of injurious insects enjoyed by this plant. 

 January 20th, 18S5. — Prof. II. Alleyne Nicholson lectured on HydraC- 



tinise and their Allies both Recent and Fossil, and rendered a 



somewhat difficult subject at once clear and interesting to all his audience. 

 The lecture was illustrated by diagrams and specimens. 



February 17th. — The Secretary, Mr. John Roy, read a paper on The 



Flora and Fauna of Snow and Ice, which we print in full else- 

 where. Mr. F. G. Ogilvie, M.A., gave a resume of the volume recently issued 

 by the United States Geological Survey, and described at some length the 



wonderful Grand Canon of the Colorado River, as detailed in the 



Report. 

 March [7///.— Mr Alex. G. (amieson, M.A., gave an account of Seals 



