2 
OAKS. 
derived from the fructification, which is itself liable to variations and 
exceptions. It is only by a comparison of stocks of different ages that 
analogous species can be distinguished, and varieties correctly referred to 
their species. 
“ I have endeavoured to arrange the American Oaks in a natural series, 
the characters of which I first sought in the fructification; but this afforded 
only unimportant distinctions, such as the position of the barren flowers, 
whether pedunculated or nearly sessile, and the size and period of the 
fruit. Neither was I able to found my distinction on the structure of the 
cup : I was obliged therefore to have recourse to the foliage, which has 
been made the basis of a division into two sections, the first containing 
the species with beardless leaves, and the second, those in »which the 
summit or lobes are terminated by a bristle. 
“ The interval between the appearance of the flower and the maturity of 
the fruit is different in different species ; and this distinction I have admit- 
ted as a secondary character. 
“ All the Oaks are proved to be monecious. We know, too, that on 
the European White Oak and other species the female flowers are situated 
above the male upon the shoots of the same season; that both are axillary; 
and that, immediately after the fecundation, the male flowers fade and fall, 
wdiile the female blossom continues advancing through the natural stages, 
till, in the course of the year, it ripens into perfect fruit. But there are 
some species whose fertile flow'ers remain stationary a whole year, and 
begin to develop their germ the second spring, probably because they 
are not fecundated the first season ; so that eighteen months elapse 
between the appearance of the flower and the maturity of the fruit. Hence 
I have formed a subdivision into species of annual and species of bien- 
nial fructification. The female flower which is axillary the first season, 
ceases to be so, of course, at the falling of the leaf. Several species are 
found upon the Old Continent whose fructification is biennial, such as the 
Cork Oak, Quercus suher, etc.” 
I have derived great assistance from my father’s work, and have 
adopted his arrangement, which perfectly accords with my own obser- 
vations. But I have inserted several new species, and have suppressed 
two that were not well ascertained : the existence of one of them is 
* doubtful, and the other is evidently a duplicate. 
The chief distinction between my wmrk and his consists in the more 
extended practical observations ; which are the fruit of my own resear- 
ches. My constant aim was to appreciate the utility of each species in 
the mechanical arts, and to point out those which are the most deserving 
of attention in Europe and America. If in this respect mine has some 
advantage, my father’s work will .always preserve its title to the attention 
of botanists and amateurs of foreign plants, by other details not consistent 
