11 PROCEEDINGS OF THE 



Mr. Ewing stated that Cephalozia Lammersiana, Hiibn., 

 Fossomhronia ccespitiforinis, De Not., and Metzgeria conjugata, 

 (Dill.) Lindbg., were new to the Scottish Flora, and that the 

 others v/ere now for the first time recorded for the districts in 

 which they had been gathered. 



An exhibition of microscopic objects afterwards took place. 



29th May, 1883. 



Mr. Robert J. Bennett in the Chair. 



Mr. D. A. Boyd reported that an excursion had been made 

 to Paisley on 26th inst. At Nethercraigs the artificial fish- 

 ponds adjoining Messrs. J. & P. Coats' works were visited, and 

 the various appliances for hatching and rearing the young fish 

 examined. The capsules of Tliamnium alopecurwni, L., a 

 moss not often found in fruit in the district, were observed on 

 moist rocks at the Gleniffer Braes. 



Mr. Peter Cameron exhibited specimens of Trientalis europcea, 

 L., and Paris quadrifolia, L., from a glen near Johnstone, and 

 stated that these plants had not been previously recorded for 

 that district. 



Mr. James Coutts exhibited a collection of Butterflies from 

 Western Africa, gathered by the late Mr. George Thomson, 

 formerly a member of the Society. He also showed a series of 

 specimens, reared by himself, of the Silk INIoth. 



Mr. Joseph Sommerville exhibited some fine specimens of the 

 Fresh- water Sponge, Spongilla fiiiviatilis, found in considerable 

 numbers adhering to logs in the Forth and Clyde Canal at 

 Port Dundas Timber-Basins, Glasgow. 



Mr. Peter Cameron exhibited several cases of Insects collected 

 for Messrs. F. Duncan Godman, and Osbert Salvin, in Central 

 America. The collection represented almost all the families of 

 the Hymenoptera, and included some very interesting Wasps' 

 nests. 



Mr. Cameron then read a paper on ** Mimicry." In the course 

 of some introductory remarks on the historical aspect of the 

 subject, he referred to the observations made by the earlier 

 naturalists on the resemblance of many insects to certain 

 organic or inorganic substances. These naturalists, however, 

 had not attempted to give any explanation of such cases 

 beyond noticing the apparent protection thus afforded to 

 the insects from their enemies. After the publication of Mr. 

 Darwin's Origin of Species in 1859 the subject acquired fresh 

 interest, and Messrs. Wallace and Bates drew special attention 

 to it by their researches. Mr. Cameron discussed the various 

 theories which had been stated with the view of explaining this 



