334 



Here we have the Potentilla evincing an affinity with three or more 

 genera; some of the Prani and the Cotoneaster showing a double 

 transition between the Poraaceae and Drupaceae ; and Delariura and 

 the abnormal fruit of Prunus Padus and P. spinosa, indicating that 

 the almond and bean tribes are not so widely separated as from their 

 outward appearance might have been imagined. 



But among the classes also we have osculant forms. Gymnogens 

 seem to partake equally of the nature of Exogens and Acrogens ; Dic- 

 tyogens are both exogenous and endogenous ; Rhizogens connect 

 Exogens with Thallogens. Among Endogens, the Alismacese and 

 Hydrocharidaceae seem to approach the Ranunculacese and Nym- 

 phseacesB among Exogens : and examples of a similar description 

 might be multiplied ad infinitum. This subject has, however, been 

 pursued far enough on the present occasion, and we must proceed on 

 our way. 



The author of the ' Observations ' falls foul of Dr. Lindley for main- 

 taining the position that " a knowledge of the properties of one plant 

 enables the practitioner to judge scientifically of the qualities of other 

 plants naturally allied to it;" and after adducing numerous examples 

 from the ' Vegetable Kingdom ' of the apparently opposite medicinal 

 properties of plants belonging to certain orders, he thus proceeds : — 



" How, with such examples before them, men will continue to per- 

 sist in maintaining the idea that if we know the properties of any one 

 plant included in these so-called natural orders, we can fairly calcu- 

 late on similar properties being possessed by others, is to me very 

 unaccountable; and still more so, that even medical men of high and 

 most deserved reputation can lend their voice in supporting the delu- 

 sion."— P. 60. 



He then quotes the opinion of Dr. A. T. Thomson, as recorded in 

 that gentleman's ' Elements of Materia Medica,' to the effect that 



" The natural system holds out so many advantages to medical 

 science, that there can be one opinion only of its superiority in a 

 practical point of view. It informs the medical inquirer not only of 

 the botanical affinities of the plants, but also supplies him with a 

 knowledge of their properties and qualities. The acquaintance with 

 the properties of even one plant of any order, enables him to form 

 some idea of the remedial value of all the other plants in the same 

 order, and, if needful, to substitute, upon fixed principles, any one of 

 them for that which is more usually employed." — P. 61. 



On this passage we have the following comment. 



" The only possible way in which I can attempt to account for such 



