the author ascertained that in the motion of the sensitive plant two distinct motions take place, the one of » 
locomotion, which is the consequence of direct violence offered to the leaves, and which occurs in the 
swellings already spoken of ; the other is nervimotion, which depends upon some stimulus applied to the 
surface of the leaflets, unaccompanied by actual violence, such as the solar rays concentrated in the focus of 
a lens. As in all cases the bending or folding of the leaves evidently takes place from one leaf to another 
with perfect continuity, it may safely be inferred, that the invisible nervous action takes place in a direct 
line from the point of original irritation, and that the cause by which this action of nervimotion is produced 
must be some internal uninterrupted agency. This was, after much curious investigation, determined by 
the author to exist neither in the pith nor in the bark, nor even in the cellular tissue filled with nervous 
corpuscles, and on which he supposes the locomotion of the swelling at the base of the petioles to depend. 
It is in the ligneous part of the central system in certain tubes supplied with nervous corpuscles, and serving 
for the transmission of sap, that Dr. Dutrochet believes he has found the true seat of nervimotion, which 
he attributes to the agency of the sap alone, while he considers the power of locomotion to depend upon 
the nervous corpuscles alone. 
Some few species of the Mimosa may be preserved in a warm inhabited room ; but they are mostly 
kept in a stove, and few of them will bear the open air even in summer. Like human beings, they are more 
sensitive in proportion to the tenderness of the nursing : like them, by living hardily, they may be fitted 
to bear the common chances of life. In the plant, this nervous sensibility is encouraged for its singularity. 
If the roots shoot through the pot at the bottom, the plant should be turned out, the roots be pared 
close, and then replaced in the same pot, or a larger, if necessary ; but they do not thrive so well in large 
pots. Great caution must be observed in watering them ; they must have little water at a time, but must 
not be suffered to remain quite dry. 
Many persons have endeavoured to ascertain the cause of the sensibility of these plants, but it has 
never yet been clearly explained. The degree varies in the different kinds: some will only contract their 
leaves on being touched; others will bend and recede, as it were courteously to acknowledge your approach, 
as that which is termed the Humble-plant. 
“ that courteous tree 
Which bows to all who seek its canopy.” 
T. Moore. 
“Looke as the Feeling-plant, which learned swaines 
Relate to growe on the East Indian plaines, 
Shrinkes up his dainty leaves if any sand 
You throw thereon, or touch it with your hand.” 
W. Browne. 
Miller, in one of the earlier editions of his Dictionary, speaks of a Calabrian philosopher who was 
driven mad by considering the mysterious nature of this plant: “Just,” continues he, “as Aristotle is said to 
have flung himself headlong into the sea, because he could not comprehend the ebbing and flowing thereof.” 
When any of the upper leaves are touched, if in falling they touch those below them, these also will 
contract and fall; so that by touching one another, they will continue to fall for some time. Mimosas are 
very common in the woods of Brazil: of one of the species, of which the wood is very light, the Indians 
make their canoes. 
The thorns of some of the Mimosas are very long, and are called, by the inhabitants of the Cape, 
Dornbush, or Thornbush. Latrobe speaks of one with which many parts of the country were nearly 
covered, with “thorns from four to six inches long, placed two and two, in an angle of ninety degrees; out 
of the inner centre of which proceeds, from a bud, a number of small pinnated leaves, resembling the 
acacia.” 
Elephants are often traced by means of these bushes, of which they eat both the leaves and roots ; 
they tear them up, and place them on their crowns, and leave the bare shrubs in that position. The thorns 
are sometimes very troublesome to travellers, where they grow pretty closely together. There is a thorny 
shrub often found growing among the Thornbuslies of the Cape, which catches the stockings, or some other 
part of the dress, and is not disentangled without some patience. The natives call it ivach en beetgen, Stop a 
little. Some of the thorns, lying very low, tear away the shoe-strings; others, less innocent in their 
mischief, tear away the skin. 
During the day-time the leaf-stalks of the mimosa are observed to form an acute angle with the upper 
part of the stem or branch to which they are attached, and the sub-leaflets spread out so as to lie nearly in- 
one plane. At night the leaf-stalks become depressed, and the sub-leaflets folded; this change occurs about 
sunset, and the opposite one, when the leaflets diverge and throw open their sub-leaflets, takes place at day- 
break. 
The Sensitive Plant signifies Timidity. 
