BOTANICAL APHORISMS. 185 
cistwe; for they depend on the proportion of its 
particular parts, or on their situation. Such cha- 
racters are not to be recommended, except where 
no better can be had, or when the situation and 
proportion are very remarkable. ‘The connate sta- 
mina are of little importance, but the stigma makes 
avery proper distinctive mark. Whether the fruit 
in most of these plants be a lerumen or a lomentum, 
it differs very much in figure: and according to the 
fioure, cloathing, or number of the seeds it con-. 
tains, may the genera be determined, 
§ 180. 
The compound flowers, or the 19th class, (§ 139), 
on account of their peculiar structure are subject to 
very different rules. In these attention must be paid 
to the common perianth, the receptacle, and the 
pappus. On these are founded the genera of this 
whole family. ‘The sex, which Linnzeus employs in 
the orders of this class, (§ 140), cannot be ap- 
proved of in distinguishing the genera, and still less 
the form of the flower. Many genera of this class 
that have no radius, nevertheless acquire it in favour- 
able situations or in warm regions, and others in 
like manner lose it. A common plant with us, the 
Bidens cernua, according to the generic character 
should have no radius ; but when it is found in very 
wet slimy ground, it grows radiate. Linné, who 
had seen both varieties, took the radiate plant for a 
particular genus, and called it Coreopsis Bidens. 
Hence it follows, that the genera Coreopsis and 
Bidens are not different, except their separation 
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