^06 PHVTOTOi\IY. 



fine cellular structure, and the superficial cells of which rise 

 up into fine prominences or pyramidal shaped knobs, on 

 which we often perceive fine drops of a fluid. This construc- 

 tion occasions the brilliant appearance which many blossoms 

 assume in the light of day, and especially during sunshine. 

 We call this fine surface the CoroUar Integument. When 

 the calyx and corolla are united, when, as in the Rosaceae, 

 the filaments seem to be fixed in the calyx, it is, however, 

 from this ccrollar integument that they arise. The parts of 

 the corolla, also, frequently alternate with those of the calyx, 

 as in the Ribes, the Rhamneae, the Salicariae, and the Melas- 

 tomeae, because both these parts spring from one base, and 

 shew the corollar integument sometimes only on the inner 

 surface and sometimes on both surfaces. In the Polygoneas 

 we find this same transition of the parts of the corolla and 

 calyx into each other, evincing that these two organs, not> 

 withstanding their usual separation, are yet very nearly re- 

 lated, and can pass into each other. 



This corollar integument covers the proper parenchyraa, 

 which is the seat of the colouring matters, and which dis- 

 plays a great variety of tints in different blossoms. The cel- 

 lular texture is by no means regulai' in blossoms; yet the 

 sides of the cells are not so bent, as they are seen to be on 

 the epidermis of the under surface of leaves. When this 

 cellular texture, the seat of the coloured fluid, is taken 

 away, we then perceive the spiral vessels, and less frequently 

 the sap-tubes: they appear in bundles on the basis of the 

 petals. But most frequently we observe them single towards 

 the circumference, apparently ramified, and anastomosing with 

 each other in great arched lines, until at the margin they 

 gradually pass away, so that the most powerful magnifiers 

 are scarcely able to shew us distinctly their extremities. 



As the spiral vessels resist maceration, very fine skeletons 

 may be prepared and kept, as well from the blossoms as from 

 the leaves. 



