338 



tion for a natural method of classification. The author himself is 

 obliged to confess, that " It is no doubt a very curious physiological 

 fact, that plants growing from seeds composed of one cotyledon, have 

 a different vegetation, mode of growth, and structure, from those which 

 grow from two ;" but he omits to state in addition, that a due considera- 

 tion of these structural and physiological differences has led to the 

 discovery of other equally important truths, which, taken in their 

 entirety, form a mass of characters than which nothing can be more 

 stable or more certain. As Lindley observes, "in Natural History 

 many facts which have been originally discovered by minute and 

 laborious research, are subsequently ascertained to be connected with 

 other facts of a more obvious nature ; and of this, botany offers pei*- 

 haps the most striking proof that can be adduced." For example : 

 the two great classes of flowering plants, Exogens and Endogens, as 

 well as the flowerless Acrogens, are now mainly distinguished by those 

 very differences in their " vegetation, mode of growth, and structure," 

 which our author has had the sagacity to perceive are combined with 

 the " single, double, or no lobe" of the embryo. Thus, in Endogens, 

 •the obscure characters of the monocotyledonous embryo and the want 

 of order in the mode in which the wood is deposited in the stem, are 

 indicated by the patent ones of parallel-veined leaves and the preva- 

 lence of the number three in the floral envelopes and reproductive 

 organs. In Exogens, the net-veined leaves and a quaternary or qui- 

 nary arrangement of the parts of the flower are equally indicative of 

 a dicotyledonous embryo and wood arranged in zones. 



We quite agree with the author in his condemnation of Dr. Steele's 

 ' Hand-book of Field Botany,' indeed we consider the plan on which 

 that work is arranged, as one of the the most unnatural of all the 

 attempts to frame a natural mode of classification ; but then we do 

 not agree with him in his assertion that "the system of Linnaeus" is 

 " the only one that has ever been contrived for leading us easily to 

 the 7iames of plants ;" for the sea catch-fly {Silene maritima), ad- 

 duced as an example of the difliculties attending the investigation of 

 plants by any other method than the Linna^an, might just as easily 

 be found out by the use of the structural method. For as " there are 

 no other Exogens with polypetalous flowers, opposite undivided leaves 

 without stipules, and stems tumid at the nodi," it is obvious that a 

 plant possessing these characters would be at once referred to the 

 Caryophyllaceae, and then the determination of its genus and species 

 follows of course. And if that species had been included in the 

 ' School Botany,' its name would as readily be found as by the ' Irish 



