604 CONSERVATIVE ORGANS. [LECT. XI. 



The lines forming the meshes which thus cha- 

 racterize the cutis of leaves, were first described 

 by Hedwig as vessels, originating in the circum- 

 ference of the pores; an opinion which is sup- 

 ported by the elder M. De Saussure and M. 

 Kieser ; and which is confirmed by the microsco- 

 pical examination of a portion of the cutis of any 

 leaf. Remarking the facility with which this part 

 of the cuticular structure can be demonstrated, our 

 surprise is excited that Sprengel, Link, Mirbel, 

 Jurine, Krocker, and others, should have ad- 

 vanced the opinion, that these reticulations form 

 no part of the real structure of the cutis, but 

 are merely the adherent fragments of the sides of 

 the subjacent cells : for, as I have already demon- 

 strated, the parenchymal cells are much smaller 

 than the cuticular meshes ; and, when the cutis 

 is sufficiently transparent, they are seen through 

 it very distinctly (4O. b. .), but not at all coin- 

 ciding with the sides of these meshes. Admit- 

 ting, therefore, that these lines are lymphatic 

 vessels, it is not improbable, as M. Kieser has 

 asserted, that they terminate by one extremity 

 in the larger vascular fasciculi ; but on this point 

 I have not been able to satisfy myself. The 

 meshes, which they form, differ very much, both 

 in form and size, in different leaves*. In al- 



* Mirbel, reasoning from the false opinion which he had 

 formed of the structure of the cutis, observes, " les differences 



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