Organization of Leaves. H7 



where the lacunae terminate there are then observed large 

 transparent reticulge of a very loose texture, which become 

 lacerated in their turn when the leaf acquires more increase. 

 I observed the same disposition in the leaves oi" the narcis- 

 sus, the hyacinth, and of leeks. 



Were we to apply this system of lacerations and lacunae 

 to all stems and leaves which have canals in their interior 

 part, it wouldj in my opinion, be giving it too much ex- 

 tent. 



Since there are several which issue from the root with 

 these canals, and the smooth close sides of which never ex- 

 hibit any laceration of the utriculi, I therefore entertain no 

 doubt that the canals found in some aquatic plants, such as 

 the nenuphar, the mereophyllum, &c. are essential to their 

 organization, and that they depend on a particular and pre- 

 determinate arrangement of the utriculi. 



Explanation of the Figures, 



(See Plates I and II.) 



Fig. 1 . This figure represents a piece of a leaf of the fri- 

 tillaria seen through the microscope. The side A is in its 

 natural state, and shows the exterior utriculi, the form of 

 which is a parallelopipedon elongated in the direction of the 

 length of the leaf. Between these utriculi are remarked 

 some of those small spherical bodies formed by the conju- 

 gate utriculi which constitute the pores. 



The side B, deprived of the pellicle, which is transported 

 to fig. 2, shows the parenchyme of the leaf of a green co- 

 Jour, much more intense than it appeared in A through the 

 |)cllicle.. This pellicle, which is formed merely by the up- 

 per face of the exterior utriculi, could not be removed but 

 by the laceration of these utriculi : their lateral faces, which 

 have remained adhering to the conjugate utriculi with which 

 they arc intimately united, are therefore seen on the paren- 

 chyme. 



The bright points seen here and there dispersed on the 

 surface of the figure, represent small brilliant points observed 

 in the parenchyme, and which are produced by the air con- 

 tained in the utricular interstices. 



Fig. 2. This figure, as already said, is th.e pellicle re- 

 moved from the surface B, fig, 1 . The upper surtace of 

 the exterior utriculi of which it is formed exhibits slight 

 undulations, produced, in my opinion, by its exposure to 

 the air. '['he oval holes with which it is perforated corrc- 

 epond to the conjugate utriculi which have remained on tho 

 11 3 parcu- 



