616 ON THE DISTINCTION OF SPECIES. 
and one that ought to be discountenanced as much as pos- 
sible. But what other tests are there, in which botanists will 
give a general acquiescence, although they thus frequently 
neglect them in practice? Some tests certainly exist, as 
floating ideas in the minds of botanists, and are occasionally 
alluded to in books. "l'hey are admitted even in the pretexts 
made for evading them, as evidenced in the ludicrous eager- 
ness with which small botanists assure us (in reference 
usually to some petty variety on which they have bestowed 
a specific name) that “it is perfectly distinct,” that “it may 
always be known by its narrow leaves,” that “it retains its 
characters in cultivation,” and so forth. Cannot those tests, 
then, be made to bear more directly on the determination of 
our true species, instead of being rather made into plausible 
arguments for defending the creation of false species? 
In the first place, let it be supposed that two plants are 
before us, which are marked by some obvious differences of 
external characters, although generally corresponding one 
with the other. Let it be next supposed, that after some 
change of soil, or other circumstance, those differences be- 
come less and less, until they finally disappear. In this case, 
‘if fully assured of the fact, botanists would agree to unite the 
two plants, and all others alike either of them, under one 
specific name. As an illustration, it may be here mentioned, 
that a root of Festuca loliacea (Huds.) was transplanted into 
my garden, in the year 1841; also a root of Festuca pratensis 
(Huds.. In this year, 1843, the former still produced 
several racemes of nearly sessile spikelets, such as are seen 
in the wild plants so named; but along with these, there 
were others in which the peduncles of the lower spikelets 
were elongated, branched, and bearing two to six spikelets 
each. The raceme was thus changing into a paniele, which 
closely resembled some of the least-branched panicles pro- 
duced from the root of Festuca pratensis. Though the trans- 
formation was not quite complete, it had proceeded fat 
enough to show that these two supposed species are only 
forms of one natural species. : 
