42 THE IMITATION, IN CLOSED CASES, OF 
have seen many plants taken from the same 
locality (Turk’s Waterfall, Co. Kerry), which 
have fructified profusely. 
I remain, my dear Sir, 
Yours very respectfully, 
Rob. Callwell. 
The above communication suggests one or two 
reflections of practical application. We see, first, 
how possible it is to grow some plants in closed 
cases, in even more than their native luxuriance. 
I believe it would be very difficult, if not im- 
possible, to find such a patch of Trichomanes as 
is above described, either in Ireland or in any 
part of the world. The next reflection is, that, 
in obedience to well-known physiological laws, 
whenever the foliage of a plant is developed to a 
greater extent than usual, the tendency to pro- 
duce fruit becomes proportionally diminished, 
and sometimes, as in the above instance, ceases 
altogether — not one frond out of the two hundred 
and thirty fructifying. It would be interesting 
to watch the effect of exposure to stronger 
light, and of a diminished supply of water. We 
further learn that ferns, like other plants, vary 
much as to their natural states, and that, in 
order to grow even the British ferns in one case, 
it will be necessary to pay attention to their 
