NATURAL HISTORY MISCELLANY. 105 
most conveniently, separable. So again, in many other Lichens (sup- 
posed now to contain usneic acid) as Parmelia and Lecanora, Cladonia, 
etc., the reaction, if it occur, is yellow, or greenish-yellow, and serves to 
least, on no other than the kind of evidence above given, to be ‘‘species,” 
that botanists are concerned 
I have gone through a large part of my North American and exotic 
Lichens in the light afforded by these experiments, and found the facts, 
through Cladonia, wherein forms, agreeing in almost every other respect, 
are seen to differ, and in the same way, in their apas with potash ; 
and his list of such forms might yet be extended. C. delicata, of the first 
series below, is complemented, it appears (Leighton’s Shaaban p- 6) by 
a C. subdelicata ; and C. athelia bears, a little doubt, a similar relation 
to O. Santensis. Nor does there appear to be reason for estimating the 
value of the terms of these parallel ER as, for example, 
Not tinged Tinged yellow by Potash. 
Cladonia gracilis, . . . . “Oladonia ecmocyna,” 
Cladonia degeneranis, . . . “Cladonia lepidota,” 
“Oladonia subdelicata,” . . Oladonia delicata, 
“Cladonia bacillaris,” . . . Cladonia macilenta, 
and so on, any higher or otherwise than in C. furcata; wherein we are 
told (Leighton’s Cladoniæ, p. 9) Dr. Nylander does not consider the chem- 
ic: i h 
spores) should not az as properly determinable by these reagents 
nothing else, as spec 
The observations es ae are, however, plainly incomplete; and derive 
from this perhaps not a little of their interest. Parmelia perlata is thus 
said to differ specifically from its var. olivetorum Ach., by failing to show 
any red tinge with Chloride of Lime; the difference already recognized 
being regarded as sufficiently corroborated by the new one. But all speci- 
mens of P. olivetorum are not so distinguishable, as compare the excellent 
ones in Welwitsch’s Portuguese collection, No.75, and Massalongo’s Ital- 
ian, No.325; and the assumed organic diversity thus failing. there is left 
only the (in itself uncertain) merely chemical one. It is much the same with 
. levigata and its variety revoluta Nyl. (Synopsis, p- ng the last being 
now taken, and on the same evidence, to be distinct in species from the 
first. We have here a better ma mee difference in botanical character, 
AMER. NATURALIST, VOL. II. 
