REPORT ON THE PHILOSOPHY OF BOTANY. 53 



instances where one flower grows from within another. And 

 finally, 6. Proliferousness {Ecblastesis), when buds are deve- 

 loped in the axillae of the floral organs, so as to convert a sim- 

 ple flower into a mass of inflorescence. A very considerable 

 number of instances are adduced in illustration of these divi- 

 sions, and the work will be found highly useful as a collection 

 of cvirious or important facts. 



The doctrines of morphology, and the evidence in support 

 of them, may now be considered so far settled as to require but 

 little further illustration for the present. This is, however, 

 only true of flowering plants : in the whole division of flower- 

 less plants there has been scarcely any attempt to discover the 

 analogy of organs, and to reduce their structure to a correspond- 

 ing state of identification. I some time since* endeavoured to 

 excite attention to this subject, by hazarding some speculations 

 which had at least the merit of novelty to recommend them ; 

 but I cannot discover that any one has since turned his atten- 

 tion to the inquiry, although it must be confessed that the com- 

 parative anatomy of flowerless plants is among the most inter- 

 esting topics still remaining for discussion, and that it is rather 

 discreditable to Cryptogamic botanists that the elucidation of 

 so very curious a matter should be postponed to the compara- 

 tively unimportant business of distinguishing or dividing genera 

 and species. 



Gradual Development. — The theory of the gradual deve- 

 lopment of the highest class of organic bodies, in consequence 

 of a combination and complication of the phaenomena attendant 

 upon the development of the lowest classes, has acquired so 

 great a degree of probability among animals, that it has become 

 a question of no small interest whether traces of the same, or a 

 similar law, cannot be found among plants. In an inquiry of 

 such a nature, it seems obvious that attention should in the first 

 instance be directed to a search after positive and incontestable 

 facts, and that mere hypotheses should in the beginning be to- 

 tally rejected. The only circumstances that occur to me as 

 bearing directly upon this point are the following. It has been 

 ascertained by M. Mirbel, in his memoir on the Marchantia, 

 that the sporule of that very simple plant is a single vesicle, 

 which, when it begins to grow, produces other vesicles on its 

 surface, which go on propagating in the same manner, every 

 new vesicle engendering others ; and that different modifica- 

 tions of this process produce the different parts that the per- 

 fect plant finally develops. 



* Outlines of the First Principles of Botany, p. 333, &c. Introduction to ihe 

 Natural System of Botany, p. 313, &c. 



