44 IMPERFECTION OF THE GEOLOGICAL RECORD 



by exchanging with naturalists who had collected in Greenland, 

 Labrador, and Norway, I employed myself, summer after 

 summer, in dredging both on the south and north shore of 

 the St. Lawrence, until able at length to discover in a living 

 state, but under different conditions as to temperature and 

 depth, nearly every species found in the beds on the land, 

 from the lower boulder clay to the top of the formation, and 

 from the sea-level to the beds six hundred feet high on the 

 hills. Not only so : I could ascertain in certain places and 

 conditions all the peculiar varieties of the species, and the 

 special modes of life which they indicated. Thus, in the cases 

 of the Peter Redpath Museum, and in notes on the Post- 

 pliocene of Canada, the gap between the Modern and the 

 Glacial age was completely filled up in so far as Canadian 

 marine species are concerned. The net result was, as I have 

 elsewhere stated, that no change other than varietal had 

 occurred. 



In studying the fossil plants of the Carboniferous, so abundant 

 in the fine exposures of the coal formation in Nova Scotia, 

 two defects struck me painfully. One was the fragmentary 

 and imperfect state of the specimens procurable. Another 

 was the question, What preceded these plants in the older 

 rocks? The first of these was to be met only by thorough 

 exploration. When a fragment of a plant was disclosed it was 

 necessary to inquire if more existed in the same bed, and to 

 dig, or blast away or break up the rock, until some remaining 

 portions were disclosed. In this way it has been possible to 

 obtain entire specimens of many trees of the Carboniferous ; 

 and to such an extent has the laborious and somewhat costly 

 process been effectual, that more species of carboniferous trees 

 are probably known in their entire forms from the Coal forma- 

 tions of Nova Scotia than from any other part of the world. 

 I have been amused to find that so little are experiences of 

 this kind known to some of my confreres abroad, that they 



