22 REMARKS ON THE DISTINCTIVE CHARACTERS OF PLANTS. 



Figs. 7, 8, 9- Also represent similar sections of the Weymouth Pine. 



On examining other species of Coniferae, we find the same general ap- 

 pearances, with slight modifications. It is therefore an essential character 

 of these trees, that the walls of the elongated cellules, when viewed on the 

 sides next to the medullary rays, should present a single series of globules 

 or circular pores, and that the other sides of these cellules, or those facing 

 the bark, and the pith should be compact and uniform. 



The Cycadeae are said to be the only plants known to resemble the 

 Coniferae in these respects ; but as I have not been able to procure speci- 

 mens of them for examination, I am unable to say any thing of importance 

 respecting their structure. 



