1850.] Linnean Society. 107 



exceptions. Thus for instance he considers the posterior position of 

 the single carpellum of Cei-atophylleee, corresponding as it does with 

 that of Piperaceee and their allies, and differing as far as known from 

 that of any other order with which it could be associated, as a strong 

 argument of affinity. He refers to the case of two-celled ovaries 

 with unequal cells, and regards the superior development of the 

 larger cell or of the corresponding stigma as indicative of what would 

 be the position of the single carpellum, were the ovary to be so 

 reduced. These remarks are followed by observations on the 

 general character of his divisions and subdivisions, and by some 

 notes on the position of carpella as regards endogenous plants and 

 Rhizanthecs, and on the relation of didynamous stamens and carpella 

 as regards their order of suppression ; and the first part of the 

 memoir concludes with some remarks on the difficulty of determining 

 with precision the true axis of the inflorescence, and the means of 

 obviating this difficulty in certain cases. 



The second part of the memoir is more especially devoted to the 

 consideration of ovaries consisting of a single carpellum, to the rela- 

 tions borne by this carpellum to the axis in various families referred 

 by the author to each of his two principal divisions, and to the 

 grounds from which this relation is deduced. This being entirely 

 matter of detail is scarcely susceptible of analysis, but some of the 

 incidental observations connected with it may properly be noticed 

 here. Mr. Clarke states that in Scleranthus annuus the funiculus is 

 uniformly jDOsterior to the seed and on the same side with the coty- 

 ledons, in which character that plant diifers from Chenopodece and 

 Amaranthacece, and as far as he has been able to ascertain from Ille- 

 cebrea, in which the funiculus is either anterior or lateral, and the 

 cotyledons (in pendulous seeds) on the opposite side of the seed or 

 less frequently lateral. Of thirty-two ovaries of Circcea alpina, thirteen 

 had two cells with an ovule in each, but the posterior cell constantly 

 smaller than the anterior, in twelve the posterior cell was empty, 

 and in seven entirely absent ; and this analogy with some particu- 

 larities in structure led him to regard the single cell of Hippuris as 

 most probably resulting from a single anterior carpellum. He shows 

 by a series of diagrams that the position of the fertile cell in Valeri- 

 anece is always lateral and external ; and observes that in the genera 

 with an irregular corolla it always bears the same relation to the 

 irregularity of the flower. He infers from an inferiority of develop- 

 ment of the posterior carpellum in Stylidium graminifoUum, that if 

 the ovary in that genus were reduced to a single carpellum, that 

 carpellum would be anterior ; a case which he has since found to 



