316 JOURNAL OF THE PLYMOUTH INSTITUTION. « 
particular place, are too ready to conclude it is there because it finds 
the spot best adapted to its requirements, so far as soil and like 
conditions are concerned, when after all there may be no such 
special adaptations existing. In our own lovely Plym Valley we 
find diminutive specimens of Ranunculus purviflorus, Tcesdalia 
nudicaulis, Lepigonum rubrum, and Trigonella ornithopodioides 
growing on the refuse thrown out from the quarries of Cann and 
Rumple, yet we know they all would attain larger size in a deeper 
soil; but here the surrounding country is so occupied by oaks, 
brambles, and strong-growing herbaceous plants, that it affords no 
place for them, so the conclusion seems forced on us that the com- 
paratively minute and weaker forms have been driven to the spots 
we see them filling. 
Again, we have a wild garlick (Allium oleraceum) growing sparsely 
on the limestone beds to the east of Plymouth, lying between the 
Plym estuary and Plympton and Elburton on the east. It is not 
known elsewhere in Devon or in Cornwall, and we might at first 
be led to suppose that there exists some principle in the soil of the 
locality indicated specially suited to it; but having some years ago 
removed a root or two to a small garden in the northern part of 
Plymouth, where the substratum is Devonian slate, I have since 
had the conclusion forced on me that there is no special connection 
between anything contained in the limestone soil and the plant ; 
for the garden specimens have attained a luxuriance far beyond 
the wild state, and have shown an enormous rate of increase 
through the bulblets formed on their heads. Yet this is a plant 
that in its native condition on our limestone beds seems: not to 
have at present the power of increasing as a species or enlarging © 
its area, year after year about as many specimens sprouting up on 
the old wall or grassy bank. Probably it is a difficulty in main- 
taining its ground against others better able to adapt themselves to 
surrounding conditions that keeps it thus local and sparse. The 
facts just given respecting this garlick pointedly illustrate the 
following remarks of Darwin: “If we forget for an instant that 
each species tends to increase inordinately, and that some check is 
always in-action, yet seldom perceived by us, the whole economy 
of nature will be utterly obscured.”* 
Bearing in mind the increase of the allium when it was freed 
from other plants, we may see how much man in gardening opera- 
* “Origin of Species,” ed. 6, p. 297. 
