NATURAL CONDITIONS OF PLANTS. 15 
greater powers of adaptation. It is not, perhaps, 
going too far to assert, that no two plants are 
alike in this particular, or, in other words, that 
the constitution of every individual plant is dif- 
ferent ; and nothing would he more delusive than 
to imagine, that because two plants are found 
associated in a state of nature, the same treat- 
ment would be applicable to both, or that both 
would he equally amenable to culture. Thus 
the Hymenophyllum and the common London 
pride (Saxifraga umbrosa) are found growing to- 
gether in rocks on the shores of the Lake of 
Killamey ; the one is so difficult of culture that 
the Irish have a saying, 11 that he who can grow 
the fairy fern is born to good fortune,” whilst 
the Saxifrage, on the contrary, will grow in any 
situation, and will last for years, without the 
slightest attention, under the most depressing in- 
fluences. 
We have another remarkable example in the 
auricula, which is only found indigenous in the 
Alps, growing in company with plants, mostly 
very difficult of culture. 
The Cerasus virginiana affords an interesting 
illustration of the effects of climate upon vegeta- 
tion : in the southern states of America it is a 
noble tree, attaining one hundred feet in height ; 
in the sandy plains of the Saskatchawan it does 
