40 W. H. Beeby on 



to distinguish. As many as six or eight hitherto undescribed 

 species were met with during a six weeks' stay in Westmoreland, 

 chiefly in bog-pools and the smaller momitain-streams. Several 

 of these were described : and the two processes of reproduction, 

 by division and by conjugation, dwelt on. The process of division 

 or fission was illustrated in the case of a common mountain spe- 

 cies, Stcnirastrum teliferum, and a description given of the mode 

 in which the spiny processes on the mature frond may be seen to 

 develop under the microscope, affording one of the most rapid 

 instances of growth in the vegetable kingdom. 



The lecturer concluded with some general remarks on the 

 distribution of species. As regards the Desmidiea, many of the 

 commonest species are cosmopolitan, while others appear to be 

 found exclusively or chiefly in particular countries or at particular 

 altitudes. The theory of the evolution of species by natural 

 selection is in no way opposed to the fact of the constancy of 

 species from age to age, where the climatic conditions which 

 have surrounded that species have been constant. The wide 

 diffusion of extremely well-marked species over the whole globe 

 presents a much greater difficulty. It was suggested that pos- 

 sibly the explanation might be found in the comparative 

 quiescence of cosmic phenomena in the present age as contrasted 

 with those which prevailed in past geological ages. 



The lecture was illustrated by diagrams and microscopical 

 specimens. 



55. — On some Eecent Additions to the Flora of Surrey. 

 [Abstract.] 



By W. H. Beeby. 



(Eead December 9th, 1885.) 



On the last occasion that I had the pleasure of reading a paper 

 before you, I was able to record that during the year 1884 about 

 ten species had been added to our Surrey list, these being either 

 entirely new records or confirmations of old records made on 

 very doubtful or insufficient authority. The result of the past 

 season's work presents a considerable contrast to that of the 

 previous one. Apart from critical forms and varieties, there are 

 no additions whatever to be recorded ; and as the time given to 

 investigation has been quite as great as in 1884, I think we may 

 fairly conclude that our list is now a tolerably complete one, so 

 far as the ordinary plants of the county are concerned — of course 

 excepting critical forms and great rarities, a few of which may yet 

 turn up in isolated localities. Still, notwithstanding the absence 

 of any new species records, some interesting confirmations have 

 resulted from the past year's work, as well as the re-discovery 

 of one species which had become extinct in its original station. 



