ORDER MONOGYNIA. 
211 
ly attempted to seize ; after the insect, overcome by the closeness 
of the grasp has expired, the leaf again unfolds itself. These 
movements are accounted for, by attributing to the plant a power 
of irritability, which is excited by the touch of any object. 
Although we account for the phenomenon by attibuting it to 
the irritability of the plant, we have only removed the difficulty 
by adducing a cause which itself remains to be explained. We 
shall in a future lecture make some remarks upon the irritability, 
or as it is sometimes called, sensibility of plants ; many curi- 
ous and interesting facts, respecting this singular property of 
vegetables, may be collected ; many plausible theories to account 
for it have been given ; but the efficient cause is too deep for 
man to penetrate ; his feeble faculties cannot comprehend the 
designs and operations of Almighty Power. 
The Second Order of the tenth class contains the Hydrangea , 
an elegant East Indian exotic ; a species of this plant, a shrub 
with white flowers, is said to have been found on the banks of 
the Schuylkill river. 
The Pink (Dianthus) belongs to an extensive natural order, 
Caryophyllece, which is distinguished by having five petals in- 
serted with claws. One native species of the genus Dianthus, 
called armeria , or Wild pink, has been found in New-Jersey and 
New England. 
The Third Order , or Trigynia, contains some plants which 
belong to the same natural order as the pink. 
The Fourth Order, Tetragynia, is not important. 
The Fifth Order, Pentagynia, produces a plant Agrostemma , 
known by the name of Cockle, this is very common in fields ; 
although troublesome and regarded but as a weed, it is a hand- 
some pink-like plant, bearing a deep red or purple blossom ; in 
its genuine character it differs little from the pink genus, except 
in having five pistils instead of two, on which account it is 
placed in the fifth order. 
Here is also found the Sorrel, (Oxalis,) which produces the 
oxalic aeid, similar in its properties to the juice of lemons ; 
though poionous this acid is useful in taking the stains from linen. 
In the Tenth Order is the Poke-weed, (Phytolacca,) a 
very common plant ; the fruit of which consists of large, dark 
berries, often used by children for the purpose of colouring 
purple. The young shoots are tender and are sometimes eaten 
as a substitute for asparagus. The flower of this plant presents 
us with 10 stamens, 10 styles, a calyx with 5 white leaves, re- 
sembling petals, a berry superior, (above the germ,) with 10 
cells and 10 seeds. 
We have now finished a review of the ten first classes, or the 
Dionaca — Hydrangea — Pink — Cockle — Sorrel — Poke-weed. 
