Deposits containing Fossil Plants. 49 



wise stated, I have myself determined the plants included 

 in the lists. 



Various points have to be taken into consideration if 

 we desire to avoid failure or useless labour in our search 

 for seeds or leaves in a determinable state. The deposits 

 most likely to yield satisfactory results are not such as 

 one would at first sight select as best for the purpose. 

 On consideration, it will readily be understood that a 

 wide-spread peat-moss will yield little but remains of bog- 

 plants; an extensive lacustrine deposit will contain few 

 but aquatic species; a broad alluvial flat may only pre- 

 serve plants of the marsh and wet meadow. The work of 

 collecting at best is very laborious, and, in order to obtain 

 with the least amount of trouble an insight into the fossil 

 botany of any particular period or district, it is best, where 

 practicable, to select for examination the deposits of a 

 small stream which flowed through a varied country. 

 These will yield not only seeds of the aquatic and marsh 

 plants that lived on the spot, but also of a variety of dry- 

 soil plants and trees which grew on sandy or rocky banks 

 overhanging the channel. They will also yield seeds of 

 numerous species which grew somewhat further away, and 

 were brought by birds and dropped from the overhanging 

 boughs ; and will contain winged seeds transported by the 

 wind. 



It may be thought that plants of all these descrip- 

 tions will be found in a lake or peat-bog, and no doubt it 

 is so; but they will be so rare, and mixed with so large a 

 proportion of seeds belonging to some few aquatic plants, 

 that the time spent in searching for them will be largely 

 increased. I speak of this from personal experience ; for, 

 through an imperfect appreciation of this difficulty, much 

 time was lost in my earlier work, and samples of clay, 

 collected and washed with great labour, often yielded 



B 



