300 ON THE PROGRESSIVE DEVELOPMENT, &C. 



primary divisions of the vegetable kingdom are characterized 

 by these peculiarities in the structure of the embryo. 

 The distribution of plants, however, according to this 

 arrangement, is very unequal. Of about 44,000 species 

 known to exist, 38,000 are flowering plants, of which number 

 32,000 are dicotyledonous, and only 6000 monocotyledons. The 

 remaining 6000 are cellular plants, and destitute of cotyledons, 

 the structure of their seeds being, indeed, from the extreme 

 minuteness of their organs, very little known, and probably 

 altogether different from that of the seeds of vascular plants. 

 They are perhaps more analogous to bulbs than to perfectly 

 formed seeds. 



A bulb consists of an internal firm pulpy substance, 

 surrounded by a filmy envelope or cuticle, and coated with 

 several layers of a loose fibrous expansion. In the centre 

 of the pulpy substance will be found the future plant, which 

 may frequently be observed fully developed in all its parts 

 before there is any appearance of external vegetation. *' If the 

 bulb of the tulip is taken up in the beginning of the month of 

 January, and carefully bisected in a line passing through its 

 longitudinal axis, the petals, the stamens, the pistil, and the 

 incipient stem may be already all distinctly perceived, small and 

 delicate in their appearance, but complete in all their parts."* 



Buds contain the rudiments of leaves and flowers. They 

 consist of a scaly envelope, inclosing the proper bud, which is a 

 pulpy substance, with numerous interlaced fibres, and sur- 

 rounded by a thin cuticle. "In the month of March, 1810," 

 observes Mr. Keith, " I opened up a bud of the horse chesnut 

 that had not yet burst its scales. The scales, which were about 

 fifl;een or sixteen in number, being removed, were found to 

 contain one pair of opposite leaves, now laid bare, the divisions 

 of which were closely matted together with a fine down. The 

 leaves upon being opened were found to inclose a flower-spike, 

 consisting of not less than a hundred florets compactly crowded 

 together, and each enveloped by its own downy calyx, which 

 when opened discovered the corolla, stamens, and pistil distinct, 

 the rudiments of the future fruit being also discernible in the 

 ovary."f 



This singularly curious fact affords a striking illustration of 

 the general correctness of the principles attempted to be es- 

 tablished in the preceding observations. But these remarks 

 have already extended to too great a length, and to enlarge further 

 upon the subject would exceed our allotted limits. Enough has, 

 however, been brought forward to shew the nature of these curious 

 investigations, and should any of the readers of " The Analyst" 

 be induced, by the deep interest which attaches to it, to pursue 

 the inquiry, these pages will not have been written in vain. 



♦ Keith, in Brewster's Journal, August, 1834, p. 114. f Ibid, p. 115. 



