24 RICHARDSON—ON TWISTING OF LEAVES. 
confusion which exists in the descriptive accounts of some of 
these species. 
In conclusion, it may be pointed out that in the silver firs 
(Adzes) and in the hemlock firs (Zsuga) species occur in which 
the leaves are not distinctly flattened, and where, as in the true 
spruces (Picea § Eupicea), the stomata are more or less evenly 
distributed over the four faces of the leaf. This occurs in such 
species as Abies Pinsapo, A. nobilis, A. magnifica, and others, 
amongst silver firs, and in 7saga Hookertana of gardens amongst 
hemlock firs. In such cases there is, of course, as in the case of 
spruces, no pseudo-distichous arrangement. 
that the resin-canals are pri in the actually, as well as the morphologically, under 
part of theleaf. About Lf. Breweriant, a species of which I have not seen specimens, 
I am unable to seeihits an opinion . oe whether the leaves twist on the horizontal 
shoots or not. JBeissner (‘‘ Handbuch der Nadelholzkunde,” p. 350) places it 
amongst the true spruces al Putte = Willkomm), in which no twisting of the leaf base 
occurs ; but Professor Sargent says.(‘‘ Silva of North America,” Vol. xii, p. 52) ‘‘it 
most eercorse in -leaf structure and = the form of its cone-scales the flat-leaved 
# O of the Balkan arenes Judging from the figures alone (both of the 
« Gardeners’ Chronicle” and o *¢ Silva > it would appear that the stomata are 
confined to one leaf-surface acl, a from the position in which the canals are 
shown, no doubt this is the upper one, as in the other flat-leaved species. I therefore 
incline to Professor Sargent’s opinion that it is more closely allied to the flat-leaved 
species than to the true spruces. 
