158 The Scottish Naturalist. 



been found on ice only, on the glaciers of Greenland and Scandinavia; 

 and a few are pretty much confined to snow, though not exclusively 

 so. They have a very wide range of distribution. Many of our own 

 species are identical with those of Greenland, Spitzbergen, and Novaia 

 Zemlia, on the one hand, and with those of Brazil and India, on the 

 other ; and most ot the species found in Japan are the same as the 

 Scandinavian, that is, practically the same as our own. 



Like the Diatoms, the study of the Desmids and the improvement 

 of the microscope came together. I have been unable to ascertain 

 that anything whatever was attempted in this way in our district, till 

 the year 1840. Mr Ralfs began about that time to make preparations 

 for his beautiful work on British Desmidietz, which appeared in 1848. 

 He had two able assistants in the north, to whom he very frequently 

 refers, the late Professor Dickie, F.R.S., and Mr Peter Grant. The 

 latter has been dead for many years, indeed I never met him. He 

 was an indefatigable collector, and sent material to Ralfs from all parts 

 of Aberdeenshire and Banffshire. Dr. Dickie examined for himself; 

 but was in close communication with Ralfs, to whom he gave much 

 assistance. From 1849 till i860 he resided in Belfast, and before his 

 return to Aberdeen in i860 he had practically given up the study of 

 Fresh Water Algae, having found that of Marine Algae much more 

 congenial. In the latter department, I need hardly remind you, 

 that for many years he had no superior. This statement satisfactorily 

 accounts for the small list of Desmidiece given in his "Botanist's 

 Guide," amounting, I think, to only about 70. After Dickie and 

 Grant, I am not aware of anyone having taken up this subject 

 systematically, in this district till I began it myself, sixteen or seven- 

 teen years ago ; and at that time the only other person I knew of 

 who worked at Desmids was Mr. Archer of Dublin ; we were mutually 

 indebted to Dr. Dickie for bringing us into correspondence, a 

 correspondence which soon became close and valuable, especially to 

 me. Since then, students of this subject have become more numer- 

 ous, though still far too few. 



Recently, with the object of perhaps publishing something on 

 Scottish Desmids, and with a view to ascertaining their distribution 

 through the country as accurately as possible, I have been searching 

 for any lists that may have been printed for particular localities. In 

 particular, I looked through the earlier volumes of the Transactions 

 of the Botanical Society of Edinburgh, as likely repositories for such. 

 There I found two lists, both for 1855; the first by Mr. Geo. Lawson, 

 from West Lomond Hill, comprising 29 species, all common ; the 

 second from Breadalbane Mountains by Mr. Hugh C. Stewart, com- 



