2/6 DECOMPOSITE ORGANS. CHAP. I. 



SECTION V. 



Gems. 



Divided IN the previous description of the external struc- 

 species. ture of the plant, it has been shown that there 

 exists among the different tribes of vegetables four 

 distinct species of gems two peculiar to perfect 

 plants, the bud and bulb and two peculiar to im- 

 perfect plants, the Propago and Gongylus ; the lat- 

 ter being denominated simple gems, because furnish- 

 ed with a single envelope only ; and the former 

 being denominated compound gems, because 

 furnished with more than a single envelope. 



SUBSECTION I. 



Insists The Bud. Buds, as was observed in the former 

 book, are composed externally of a number of 

 spoon-shaped scales overlapping one another, and 

 converging towards a point in the apex, and often 

 cemented together by means of a glutinous or 

 mucilaginous substance exuding from their surface. 

 If these scales are stripped off and dissected under 

 the microscope, they will be found to consist, like 

 the leaves or divisions of the calyx, of an epidermis 

 enclosing a pulp interspersed with a net-work of 

 fibres, but unaccompanied with longitudinal threads, 

 at least in such specimens as I have dissected. 

 The epidermis, on the outer side of the scale, is of 



