710 Mr. Brown on the Organs and Mode of 



deous plants as forming the whole body of the nucleus, and 

 consequently being destitute of albumen, agrees with the ac- 

 count first I believe published by M. Du Petit Thouars*, and 

 very soon after by the late excellent Richard +. 



The only other remark I have to make on the fructification 

 of this family, is, that the seed itself, as well as its funiculus, 

 is entirely without vessels, and that the funiculus, which in the 

 ripe seed is inserted into the testa close to one side of its open 

 base, can hardly be traced beyond that point. 



I shall conclude my observations on Orchideae with a notice 

 of some points of their general structure, which chiefly relate to 

 the cellular tissue. 



In each cell of the epidermis of a great part of this family, 

 especially of those with membranaceous leaves, a single circular 

 areola, generally somewhat more opake than the membrane of 

 the cell, is observable. This areola, which is more or less 

 distinctly granular, is slightly convex, and although it seems 

 to be on the surface is in reality covered by the outer lamina 

 of the cell. There is no regularity as to its place in the cell ; it 

 is not unfrequently however central or nearly so. 



As only one areola belongs to each cell, and as in many cases 

 where it exists in the common cells of the epidermis it is also 

 visible in the cutaneous glands or stomata, and in these is always 

 double, — one being on each side of the limb, — it is highly pro- 

 bable that the cutaneous gland is in all cases composed of two 

 cells of peculiar form, the line of union being the longitudinal 

 axis of the disk or pore. 



This areola, or nucleus of the cell as perhaps it might be 

 termed, is not confined to the epidermis, being also found not 

 only in the pubescence of the surface, particularly when jointed, 



* Hist, des Orchid, p. 19. t Mem. du Mus. d'Hist. Nat. iv. p. 41. 



as 



