The observation of these and some analogous monstrosities, 

 raising the suspicion that the distinction between foliar 

 organs and axial organs is not absolute, led me to examine 

 into the matter ; and the result has been the deepening of 

 this suspicion into a conviction. Part of the evidence is given 

 in Appendix A 



Some time after having reached this conviction, I found on 

 looking into the literature of the subject, that analogous ir- 

 regularities have suggested to other observers, beliefs similarly 

 at variance with, the current morphological creed. Diffi- 

 culties in satisfactorily defining these two elements, have 

 served to shake this creed in some minds. To others, 

 the strange leaf-like developments which axes undergo in 

 certain plants, have afforded reasons for doubting the 

 constancy of this distinction which vegetal morphologists 

 usually draw. And those not otherwise rendered sceptical, 

 have been made to hesitate by. such cases as that of the 

 Nepaul-barley ; in which the glume, a foliar organ, becomes 

 developed into an axis, and bears flowers. In his essay — 

 " Vegetable Morphology : its History and Present Condi- 

 tion," * whence I have already quoted, Dr Masters indicates 

 sundry of the grounds for thinking, that there is no impassable 

 demarcation between leaf and stem. Among other difficult- 

 ies which meet us if we assume that the distinction is abso- 

 lute, he asks — -" What shall we say to cases such as those 

 afforded by the leaves of Guarea and Trichilia, where the 

 leaves after a time assume the condition of branches and de- 

 velop young leaflets from their free extremities, a process less 

 perfectly seen in some of the pinnate-leaved kinds of Berberis 

 or Mahonia, to be found in almost every shrubbery ? " 



A class of facts on which it will be desirable for us nere to 

 dwell a moment, before proceeding to deal with the matter 

 deductively, is presented by the Cadacece. In this remark- 

 able group of plants, deviating in such varied ways from the 

 ordinary- phsenogamic type, we find many highly instructive 



* See British and Foreign Medico -Chirurgical Review for January, 1S62. 



