278 ! Dr. Surru's Defeription of 
important fpccific ones. If 1 am not too fanguine; I have met witt 
as fatisfactory a mode of determining fpecies in Mentha by the calyx 
and flower-ftalks,. particularly with regard to the pubefcence of 
thofé-parts and its various direétion. This is moft peculiarly ufeful 
. in the verticillate Mints, where it is moft wanted. In one cafe we 
find the flower-ftalk and bafe of the calyx invariably fmooth and 
naked, the upper part and teetlr only of the latter being rough 
with hairs pointing upward in another the calyx is all over clothed 
with projecting horizontal hairs; in a third it is covered with hairs 
which point upward, and, the. flower-ftalk with hairs that point 
downward. Thefe circumftances appear to me invariable. I have 
examined innumerable dried as well as living fpecimens, I have 
watched their growth in different foils, always with this particular 
object in view, and have found no reafon to alter my opinion. I do 
not fay. the hairinefs of thefe parts never varies in degree, but even 
in this. refpe& i it varies much lefs than that of any ether part of the 
plant, except. in M. viridis, which is a fpiked fpecies, and it never 
varies in direction. The utility of this fource of difcrimination will 
beft appear when we come to invefligate the verticillate fpecies, | I 
fhall therefore fay no more upon it at prefent, en proceed to a 
practical illuftration of the whole. 
As this genus is Pu perfe&ly COE that no one can be more fo, 
it will be beft, after mentioning its effential generic character, to 
give an account of thofe particulars in which all the fpecies agree. 
This will prevent ufelefs epeinons in the feparate defcriptions of 
each. | 
GENERIC 
