218 Transactions. 



to elucidate the matter as was deserving' of it. Until this could be 

 done we miglit and would g-o on Iloundenng in the mire. Tliis 

 was one of the cases in which l)y judiciously interfering with the 

 balance of nature a vast amount of jjrofit might accrue to the pos- 

 sessors of our fisheries. It was like a valuable mine of wealth 

 nnworkeil. 



1th of March, 1890. 

 Major BowDEN in the Chair. 

 New Member. — Mr Robert Maxwell AVitham of Kirkconnel. 

 Donations. — Transactions of the Edinburgh Botanical Society ; 

 Annual Report of the Belfast Field Club ; Report of the Berwick- 

 shire Naturalists' Club ; Bulletin on the English Sparrow in North 

 America and North American Fauna, from the United States 

 Board of Agriculture. The Transcription of Edgar's History of 

 Dumfries from the Riddell MS. was also handed in. 



Communications. 

 I. The Succession oj Plant Life upon tJie Earth. By Mr 

 Peter Gray. 

 After a brief exposition of the nature and mode of deposition 

 of the sedimentary rock strata in which the remains of previously 

 existing plants and animals are found, the author enumerated 

 their principal sub-divisions and defined the four life periods in 

 which they have been further arranged, namely, the Azoic (with- 

 out life), the Palaeozoic (ancient life), the Mesozoic (middle life), 

 and the Kaiuozoic (new life). There were nu dates in the 

 geological record, and, as to the length of time occupied in the 

 laying down of the sedimentary rocks, there was the widest 

 diversity of opinion. Physicists, judging from the rate of cooling 

 of the globe, and other data, were unwilling to place the time 

 when it was possible for plants to exist upon it much farther back 

 than from ten to fifteen millions of years. On the other hand, 

 some geologists asked for at least six hundred millions. Of the 

 shortest of these periods, however, we could no more form a 

 competent conception than we could of eternity. Proceeding then 

 to a detailed examination of the sedimentary deposits, from the 

 earliest upwards, the author stated that though no fossils had 

 been discovered in those of the Azoic period, yet the immense 

 quantity of carbon, in the form of graphite or plumbago, occurring 



