Botany and Zoology. : 483 
rials increase, “ do the difficulties. Forms, which appeared totally dis- 
tinct, approach or blend peri indermediate gradations; charac 
stable in a Hnited number of instances or in a limited district, prove un- 
stable occasionally, or when observed o wider area ; and the prac- 
tieal question is forced v upon the iautaniasict reper. here is probably fixed 
and specific, and what is variant, pertaining to individual, variety or race? 
ation of these rich materials, certain characters were 
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assignable reasons. Such characters, rse, are not specific, 
although many of them are such as would have been expected to be con- 
Stant in the same species, and are such as generally enter into specific defi- 
nitions. Variations of this ore ———s with his usual painstaking, 
classifies and tabulates, and ev resses numerically their frequene cy 
in certain species. The inl are - benagh well to view in a systematic 
enumeration,— 
(1.) Of characters “oe Frequently vary upon the same branch: over 
a dozen such are men 
2.) Of those re candied vary upon the same branch: a smaller 
number “ these are mentioned. 
(3.) Those so rare that they might be called monstrosities, 
Then he enumerates characters, ten in number, which he has never 
found to v ary on the same branch, and which, ws gree may ped be 
Species, even these characters must be taken with allowance. In 
havir.g first brought ge ss groups of the lowest order, those forms 
which varied upon the same ock, he next had to combine similarly 
Various forms which, though de found associated upon the same branch, 
Were thoroughly blended by intermediate degrees. 
“The ooh ‘oups (varieties uh races g thus co ted, T have given 
the rank of speci i to ih e groups next abo ee suebe. which aiffer | in other 
i.e., either in characters which were not found united upon ee individuals, 
or in those which do not show transitions from one individual] to For 
the Oaks of regions sufficiently kip the mri thus formed te vate — 
ich 
factory bases, of he proof can be furnished. It is quite otherwise 
those which are represented in our herbaria fone single or few specimens. These 
are provisi species,—specie ich h er fall to the rank of simple 
va- 
—— occurring inthe same genus or in the same family. For 
example, ean - are fact Sa aves Tler, Q. coccifera, Q. acutifolia, &c., 
have the leay metimes entire and sometimes toothed upon the same | branch, 
e i rom one tree to another, I mi a hag ag ag my 
nsis to Q. Sartorii of ego vonage since these two differ only in 
their entire or ‘hate toothed ieties From the fact that the length of the 
peduncle varies in Q. Robur and d many poy ‘Oaks 1 might have combined 
Seemannii not admitted these 
Q. ii Liebm., w saliciflia Née. I have 
inductions, but have sri proof in n each particular case, Many 
