20 VEGETABLE ORGANOGRAPHY. 



the tissue to boiling in water. Du Petit-Thouars admits 

 likewise, that these cellules or utricles are bodies 

 distinct from one another. Pollini favours the 

 same opinion, from peculiar observations of his own. 

 Amici avers, that not only, by means of his microscope, 

 he can see the intervals of the cellules, which often 

 appear as angular spaces full of air, but that he can, 

 having boiled the tissue, detach the cellules from one 

 another, and observe them isolated ; so that, according 

 to him, one cannot deny the existence of these spaces 

 or intercellular passages, which are filled with air. 

 Dutrochet says, that the cellules, having been boiled in 

 nitric acid, separate, and appear as so many distinct 

 vesicles ; but moreover, where two cellules touch, the 

 wall which separates them presents a double membrane; 

 that there is never a wall common either to the cellules 

 or to the vessels ; and that the hollow organs have no 

 other mutual relation than that of contiguity. Finally, 

 Turpin admits likewise, that vegetables are entirely 

 composed of distinct vesicles, variously combined, or 

 sometimes perfectly free ; and he proposes to give the 

 name oi globulin to this vegetable element. 



The contrary opinion, maintained, it is said, first by 

 Wolf, has been vigorously adopted by Mirbel, who 

 admits as the fundamental base of anatomy, that vege- 

 tables are entirely composed of a tissue continuous 

 throughout all its parts ; that the neighbouring cellules 

 have always a common wall ; that there are also tubes 

 resembling the neighbouring cavities; that when one 

 thinks he has seen a double partition, it is because he 

 has seen by its transparency the sides of some other 

 cellule. This opinion has been adopted by Rudolphi, 

 and I myself formerly supported the elementary theory. 

 The partisans of the two opinions rest for support upon 

 the same comparison. Grew had said that the cellular 



