246 Aledichic, 



the application of a stimulus, the ends of a straight 

 fibre approach nearer to each other, and the dia- 

 meter or area of a curved or circular one is dimi- 

 nished. 



For the facts respecting the functions of vegeta- 

 bles from which the above mentioned principles 

 have been drawn, the world is indebted, among 

 many others, to Hales, Grew, Duhamel, Bon- 

 net, BuFFON, Spallanzant, Des Fontaines, 

 Gmelin, Ingeniiouz, Hunter, Broussonet, Dar- 

 win, and many of the most distinguished disciples 

 of the Linmtan school. And when the progress 

 made by them in vegetable physiology is consi- 

 dered in relation to the discoveries obtained by 

 Haller and Fontana in animal physiology, it 

 will not appear surprizing that inferences and 

 doctrines of the greatest interest have recently 

 been thence deduced. The physiological principles 

 of Brown and Darwin, which now occupy the 

 attention of so large a portion of the medical world, 

 are conclusions resulting from that great body of 

 facts. But of these more particular notice will be 

 taken under the next head. 



Theories of Generation have engaged much 

 attention during the last century. Towards the 

 close of the preceding one, Leuwenhoeck at- 

 tracted notice by his microscopical inquiries con- 

 cerning the semen viasculinum, in which he be- 

 lieved that he saw nuiPiCrous animalcula; one of 

 which was destined to form the rudiments of the 

 future embryo. This supposed discovery gave rise 

 to a theory not yet altogether exploded, according 

 to which the womb of the female only affords to 

 the embryo a lodging, and the requisite supplies 

 of nourishment. 



M. BuFFON endeavoured to prove that the fe- 

 male holds a more important share in the process 

 of geueratioUp He asserts that animalcula, or or-* 



