118 Researches respecting the 



parenchyme, and show that it is the part of these utricuU 

 which concurs to the formation of the surface of the leaf. 



Fig. 3. This figure represents a thin shce of tlie leaf, 

 which has been cut perpendicularlv in the direction of its 

 length. The lateral faces of the exterior utriculi are seen, 

 lengthwise, united to the utriculi of the parenchymc by 

 their lower face. The conjugate utriculi are seen in the 

 direction of their height and large diameter : they are not 

 united to the parenchynie. 



Fi^'. 4. This figure exhibits also a very thin slice of the 

 leaf, but cut across or in the direction of the breadth : for this 

 reason the exterior utriculi appear in their small diameter 

 as well as the conjugate utriculi, the unioi; of which is 

 ehown by a line of separation. 



The pellicle A, which has been detached from the exte- 

 rior utriculi by laceration, shows that it is formed only by 

 their superior face : it however sometimes happens that the 

 conjugate utriculi remain adhering to it. 



Fig. 5. This figure represents nearly the same object 

 as fig. 1, but much larger in its dimensions. It is chiefly 

 destined, as well as the following, to aive a precise idea of 

 the conformation of the conjugate utriculi, and of their 

 connection with the exterior utriculi. The exterior utri- 

 culi are disengaged from the parenchymc to show more 

 distinctly how the lateral faces of these utriculi, seen short- 

 ened, may have been taken for vessels : slight wrinkles, or 

 undulations, as observed in fig. 1, are remarked on their 

 upper face. 



This figure shows also the part of the conjugate utricuU 

 which is not covered by the exterior utriculi, and which 

 thereby concurs to the formation of the surface of the 

 leaf. 



Fig. 6. This figure represents a slice cut vertically in the 

 direction of the length of the leaf, with a certain inclina- 

 tion. The exterior utriculi are seen at the same time on 

 . their exterior face, and in the direction of their height ; 

 which evidently shows that what was taken for vessels is 

 nothing else than the lateral or vertical faces of these utri* 

 culi. It is seen also how the exterior utriculi are applied 

 to, and cover the conjugate utriculi. 



Fig. 7. The section represented in this figure is the same 

 as that in fig. 4 ; it has been magnified, to exhibit all its par- 

 ticulars. L may be considered the same also as the pre- 

 ceding, if we suppose it to be inverted to exhibit it in pro- 

 file. 



The superior face of the exterior utricuU is slightly con- 

 vex : 



