j>tt LT j FLOWER-GARDEN'. 439 



Oft as light clouds o'erpass the summer glade, 

 Alarm'd she trembles at the moving shade ; 

 And feels, alive through all her tender form, 

 The whisper'd murmurs of the gathering storm ; 

 Shuts her sweet eye-lids to approaching night ; 

 And hails with freshened charms the rising light." 



Naturalists," says Dr. Darwin, " have not explained the im- 

 mediate cause of the collapsing of the Sensitive plant ; the leaves 

 meet and close in the night during the sleep of the plant, or when, 

 exposed to much cold in the day time, in the same manner as when 

 they are affected by external violence, folding their upper surfaces 

 together, and in part over each other like scales or tiles ; so as to 

 expose as little of the upper surface as may be to the air ; but do> 

 not indeed collapse quite so far : for when touched in the night 

 during their sleep, they fall still farther ; especially when touched 

 on the foot-stalks between the stems and the leaflets, which seems 

 to be their most sensitive or irritable part. Now as their situation 

 after being exposed to external violence resembles their sleep, but 

 with a greater degree of collapse, may it not be owing to a numb- 

 ness or paralysis consequent to too violent irritation, like the fainting* 

 of animals from pain or fatigue ? A Sensitive plant being kept in a 

 dark room till some hours after day break, its leaves and leaf-stalks 

 were collapsed as in its most profound sleep, and on exposing it to 

 the light, above twenty minutes passed, before the plant was tho- 

 roughly awake, and had quite expanded itself. During the night, 

 the upper or smoother surfaces of the leaves are appressed toge- 

 ther ; this would seem to shew that the office of this surface of the 

 leaf was to expose the fluids of the plant to the light as well as to 

 the air." 



The sensibility of this plant is worthy of admiration, that not 

 only in the evening, or towards night, but at all hours of the day, 

 with the least touch, or concussion of air, the leaves just like a tree 

 a dying, droop and complicate themselves immediately, and pres- 

 ently after recover, resuming their former position ; so that a per- 

 son would be induced to think they were really endowed with the 

 sense of feeling. 



The cause of this, seemed so hard to be discovered, that a cu- 

 rious Malabarian philosopher, upon his observing the nature of this 

 plant, without being able to discover the cause of its sensibility, 

 ran mad ; just as Aristotle is said to have flung himself headlong in- 

 to the sea, because he could not comprehend the reason of its 

 ebbing and flowing. 



These plants are more or less susceptible of the touch according 

 to the warmth of the air in which they grow, being always more 

 irritable in proportion to the heat thereof. 



The light is not the only cause of their expansion, nor the dark- 

 ness of their contraction, for they are often closed in the afternoon 

 two or three hours before the sun descends the horizon ; and if the 

 frames in which they are kept, be, in the fore part of the day, co- 

 vered for hours, so as to render the place completely dark, yet the 

 leaves will continue their expansion. 



