190 BOTANICAL NEWS. 
if produced, would take a shorter time by a year or two.* Supposing, then, 
that the increase of female flowers amounted to only one-fifth, this would be 
for the United States alone an increase of produce amounting in value to more 
. than £20,000,000 per annum. 
The folly of excluding from our botanic gardens all those species which do 
not specially recommend themselves for their beauty to the eye of the horti- 
culturist or floriculturist, and destroying trees and shrubs which have been 
refuge for such rejected giin ts. He has Jast published (Van Voorst) the first 
part of a work devoted to their illustration, the very title of which, ‘ Refugium 
Botanicum,’ implies a censure of n viris ous system now in vogue. ay it 
be the beginning of a healthy rea 
M. Casimir de Candolle has a ane a paper on the theory of the 
leaf, which comes to us as a reprint from the Archives des Sciences de la 
Bibliothéque Universelle, and which we cordially recommend to the attention 
of botanists. The general conclusions he arrives at are that a leaf is a branch, 
the apex of which, after a certain time, becomes atrophied, or ceases to grow, 
being identically the same as those submitted in September, 1864, by various 
German botanists to the Meeting of Naturalists and Physicians at Hanover, as 
mentioned in Vol. III. p. 359 of this Tournal. 
‘Select Ferns and Lycopods, British and Exotic; comprising Descriptions 
of Nine Hundred chosen Species and Varieties,’ is the title of a new work by Mr. 
B. 8. 
publisher. There are 343 illustrations, one of them representing a grove of 
Tree-ferns (Dicksonia Antaretica), on Mount Wellington, Tasmania, taken 
from a photograph in the possession of the editor of the ‘Journal of Botany, 
and alluded to at p. 158 of our volume for 1865. The hint there thrown ouf, 
that it might be possible to grow in England Tree-ferns in the god air, is thus 
submitted. once more to the consideration of practical horticulturi 
It is gratifying to observe the scientifie spirit displaying itself i in S Vind 
in the publieation of a new periodical, * Vargasia, of which the first three 
numbers have come to hand, and which purports to be the organ of the 
xe others, a paper on Gesnera Vargasii, De Cand., by M. A 
e plant, having all th e flowers removed, placed bet 
ing rue. upper half or two- dide x them removed, would be the | ene way ot 
acing 
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plant being chee! "i an hye pre departing pv oi from the original type 
might be expected. lants so treated, the upper spike of female 
flowers developed a eal pfs shale e flowers at its apex. 
