LEGUMINOS^. CCXXIII. Mimosa. 



383 



form the whole mass of vegetable tissue, and that the same acid of original irritation, and that the cause by which this action of 

 produced other effects equally advantageous for the examination nervimotion is produced must be some internal uninterrupted 



agency. Tins was, after much curious investigation, determined 

 by the author to exist neither in the pith nor in the bark, nor 



of the most obscure parts of vegetable structure, he was induced 

 to give his attention to that of Mimosa pudica^ in the hope of 



gaining some evidence respecting the cause to which its sensi- even in the cellular tissue filled with nervous corpuscles, and on 



bility is to be ascribed. Beginning with the pith he observed a which he supposes the locomotion of the swelling at the base 



considerable number of minute globules, of a greenish colour, of the petioles to depend. It is in the ligneous part of the cen- 



intermingled among the cells, and adhering to them in an irre- tral system in certain tubes supplied with nervous corpuscles, 



gular manner. After attempting to show the probability of and serving for the transmission of sap, that Dr. Dutrochet be- 



these globules having deceived Mirble in various points of his lieves he has found the true seat of nervimotion, which he attri- 



analysis of vegetation, and especially in regard to the pores, butes to the agency of the sap alone, while he considers the 



which that botanist supposes to exist in the cellular tissue of 

 nlants, Dr. Dutrochet proceeds to remark, that the application of 

 not nitric acid to these globules renders them perfectly opaque. 



power of locomotion to depend upon the nervous corpuscles 



alone. 



Far. /3, glabrata (D, C. prod. 2. p. 426.) stem glabrous. Na- 



wlience he^ concludes that they are in fact minute cells, filled tive of St. Domingo and St. Thomas. Plum. ed. Burm. t. 202. 



with a particular fluid which is subject to become concrete by " ' ' ' ' ' 



the application of acids. Now it is known that such fluids as 



Far. y, tetrdndra (Willd. spec. 4. p. 1032.) leaflets clothed 

 with adpressed pili beneath. M. pudica, H. B. et Kunth, nov. 

 gen. amer. 6. p. 252. 



Chaste or Common Humble-plant. Fl. April, Sept. Clt. 

 1638. PL 1 foot. 



13 M. HispiDULA (H. B. et Kunth, nov. gen. amer. 6. p. 252.) 



Being examined stems prickly, and densely beset with stiflT hairs ; leaves some- 



, the globules were found to have resumed what digitately pinnate, with 4 pinnae ; leaflets linear, acute, 



their naturaj appearance. This curious fact indicated, in the ciliated, glabrous ; heads of flowers usually twin ; legumes very 



are thus altered by acids are usually dissolved and liquefied 

 again by the application of alkalies. A few drops, therefore, of 

 a solution of hydrate of potass were suffered to fall 



upon 



portion of the pith on which nitric acid had been acting, and the 

 mixture was exposed to the heat of a lamp, 

 after a few minutes, 



the 



opinion of Dutrochet, a strong and unexpected point of analogy 

 between plants and animals. According to the microscopical 

 researches of some modern observers, it has been ascertained 

 that all the organs of animals are composed of a conglomeration 

 of minute corpuscles, similar to those just described ; the cor- 

 puscles which constitute the muscles are soluble in acids, but 

 those which compose the nervous system are insoluble in the 

 same acids, and only soluble in alkalies. Now, as the chemical 

 properties and external appearance of the particles scattered 

 among the cellular tissue of plants, and constituting the nervous 

 system of animals, are the same, the author is induced to infer, 

 that the spherical particles of plants are in fact the scattered 

 ^v!^^"^s of their nervous system. This hypothesis receives 

 additional strength from the great similarity which exists between 

 medullary substance of the brain of Molusca gasteropoda 

 ^ the cellular medullary tissue of plants. In pursuit of 

 IS Idea, Dr. Dutrochet made a variety of experiments upon 

 ^e sensitive plant, the results of which seem to be these:— 

 Itrf P""^*P^^ Po^"t of locomotion or of mobility exists in the 

 ' . swelling which is situated at the base of the common and 



ver^^r! iP^^*^^"-^^ ^^ ^^^ \^s,Ye^ ; this swelling is composed of a 

 ry dehcate cellular tissue, in which is found an immense num- 

 ^f '" ^'"^rvous corpuscles ; the axis of the swelling is formed 

 son^ 1 r ^^^^'^^^ of tubular vessels. It was ascertained by 

 com -^^^^^ experiments, that the power of movement, or of 

 tiss "^^^^i^" ^"^ expansion, exists in the parenchyma and cellular 

 ueot the swelling, and that the central fibres have no spe- 

 ihe^ action connected with the molion. It also appeared that 

 energy of the nervous powers of the leaf depended wholly 

 ocr?-^" ,^^""d^^ce of sap, and that a diminution of that fluid 

 p^'^asioned an extreme diminution of the sensibility of the leaves. 

 in th^^"^^"? ^'^ remarks still further, the author ascertained that 

 place^ "^otjon of the sensitive plant two distinct motions take 

 viole' -?"^^^ locomotion, which is the consequence of direct 

 alread^^ l^^ ^^ ^^^ leaves, and which occurs in the swellings 

 UDon ^ ^P^*^en of; the other is nervimotion, which depends 

 cornn^^'"!Ik'^"^"^"^ applied to the surface of the leaflets, unac- 

 >n the f actual violence, such as the solar rays concentrated 



of ^ ?^"^ of a lens. As in all cases the bending or folding 

 ^ith^L r ^^ evidently takes place from one leaf to another 

 . .. pertect continuity, it may safely be inferred, that the in- 



Flowers red. Legumes unknown. 



Visible 



hispid. >p . S. Native of South America, near Santa Barbara. 

 Very nearly allied to M. pudica. Flowers red. 



Hispid Humble-plant. Fl.May, Sept. Clt. 1820. Sh. 1 to 2 ft. 



14 M. pudibu'nda (Willd. spec. 4. p. 1032.) stem shrubby, 

 prickly, glabrous ; leaves somewhat digitately pinnate, with 4 

 pinnae, each pinna bearing many pairs of linear leaflets ; heads 

 of flowers elliptic. Tj . S. Native of Brazil, about Bahia. 

 Flowers red. 



Blushing Humble-plant. Fl. Ju. Aug. Clt. 1818. Sh. 1 to 2 (x. 



15 M. TOMENTosA (Humb. et Bonpl. in Willd. spec. 4. p. 

 1033.) branches unarmed, clothed with silky hairs ; leaves some- 

 what digitately pinnate, with 4 pinnae, each pinna bearing many 

 pairs of oblong-linear leaflets, which are clothed with hoary silky 

 villi beneath. Pj -S. Native of South America, on the banks of 

 the river Orinoco. Kunth, mim. p. 11. t. 4. H. B. et Kunth, 

 nov. gen. amer. 6. p. 253. 

 The specific name is fallacious. 



Tomentose Humble-plant. Shrub. 



16 M. iiiRsu^TA (Moc. etSesse, in herb. Lamb.) prickles sti- 

 pular, recurved ; leaves with only 1 pair of pinnae, each pinna 

 bearing numerous linear, rnucronate leaflets ; stem hispid as well 

 as the pedicels, petioles, and rachis of leaves ; peduncles solitary 

 or twin, axillary, about the length of the petioles ; calyx hispid ; 

 legumes prickly on the margins, 3-4-jointed. 0. S. Native 

 of Mexico. Heads of flowers nearly globular, red. 



Hairy Sensitive-plant. PI. 1 to 2 feet. 



17 M. trice'phala (Schlecht. etCham. inLinnaea. 5. p. 591.) 

 leaves with 1 pair of pinnae, each pinna bearing 12 pairs of oblique, 

 ovate-elliptic, mucrpnate leaflets, which are adpressedly ciliated 

 on the margins, shining and glabrous above, but strigose beneath ; 

 petiole short ; stipulas small, filiform ; branches, rachis of leaves, 

 and peduncles scabrous from stiff" hairs ; heads tern, on long 

 peduncles, axillary, and forming a loose terminal raceme, whicli 

 IS leafy at the base. I2 • S. Native of Mexico, between Laguna, 

 Verde, and Actopan. Flowers pale red. Legumes unknown. 



Three-headed Mimosa. Shrub. 



18 M. PotYDA'cTYLA (Humb. et Bonpl. in Willd. spec. 4. 

 p. W33.) stems prickly, glabrous, pilose above ; leaves some- 

 what digitately pinnate, with 8 pinnae, each pinna bearing many 

 pairs of linear leaflets. ^2 . S, Native of Guiana, and about 

 Demerara, as well as in M aranham. Flowers purple. Heads 



nervous action takes place in a direct line from the point of flowers twin, ovate, pedunculate,. 



