4 MR. G. BENTIIA.M ON THE 



pressure of that external whorl during its growth in the bud- 

 That the indusium cannot well be a second abortive whorl of sta- 

 mens is further proved by the consideration that that whorl of 

 organs is always uniseriate in the whole Campanulaceous group of 

 orders, and that that single series exists in a perfect state in 

 Goodenovieae in its usual position at the base of, or slightly adnate 

 to the corolla ; nor can we readily compare it with a disk, as that 

 excrescence, when epigynous, is, I believe, always at the base, not 

 at the summit of the style. 



An analogy between the indusiums of Goodenovieae and the ring 

 of collecting-hairs observable in many Lobelieae has often been 

 distinctly brought forward or tacitly assumed even very lately, as 

 by Sonder in the ' Flora Capensis ' with regard to Cyphia, or by 

 Asa Gray in his note on Nemacladus in our Journal (xiv. 28); 

 but it was ably refuted by Brown when pointing out the impor- 

 tant characters separating Goodenovieae from Lobelieae. These 

 collecting-hairs are indeed in a ring below the stigma in many 

 Lobelieae and in some Campanuleae ; but in some of the former 

 and most of the latter they are differently arranged, either coTer- 

 ing the whole of the upper moiety of the stjde, or in longitudinal 

 rows, or more or less unilateral, &c. ; and in all cases they are en- 

 tirely epidermal productions, whilst the indusium is a development 

 of the substance itself of the style, 



Lindley may have come much nearer the truth when he says 

 (Veg. Kingd. 694) that it " is to be regarded as nothing more 

 than a remarkable exaggeration of the rim which surrounds the 

 stigmatic surface of Heathworts (Ericaceae), and of the plates 

 which cover the style of Cranesbills and Balsams (Geraniaceae 

 and Balsamineae) . It is, in fact, the free upper extremity of the 

 carpellary leaves, distinct from that prolongation of the placenta 

 which is named style and stigma." I cannot quite concur with 

 the latter part of this proposition ; for I should confine the term 

 placenta to that substance which more or less lines the inner walls 

 of the ovary-cells or protrudes from them and bears the ovules, 

 and regard the whole style as the prolonged apex of the carpellary 

 leaves, entire or variously lobed, or enlarged at the extremity and 

 bearing the stigmatic surface either on the summit, or within, or 

 on the margins of the lobes, or below them on the outside. And if, 

 with Lindley, we may compare the indusium with the ring sur- 

 rounding the stigma in Ericaceae, we may perhaps still better com- 

 pare it with the dilatation at the end of the style commonly called 





