148 Mil. C. DRESSEll's COTfTBIBUTIONS 



some other points. The proper place of A. Bidwelli is probably 

 also among Gummifercs. I had only seen it in fruit, when the real 

 inflorescence is not always very certain; and I doubted whether the 

 capitula were not sometimes racemose : but most probably they are 

 (as in A. pallida) solitary, with the bract in the middle of the pe- 

 duncle, the scar of which has sometimes the appearance of the scar of 

 of a pedicel. Dr. Mueller's specimens. No. 76, are also without spines, 

 and have much more numerous pinnae than he describes (15 to 20 pairs 

 with leaflets barely 2 lines long). These are, like Bidwell's, in fruit 

 only. There is, however, a flowering specimen of Dr. Mueller's marked 

 7b, from M'Adam's Range, which answers better to his character, and has 

 the stipular spines of Gummiferce. In it the pinnae vary from 3 to 1 1 

 pairs, and the leaflets are 3 to 4 lines long. These clearly indicate the 

 affinity of the species with A. suherosa, from which it differs in the usually 

 numerous pinnae and the broader pod. It remains to be proved whether 

 it be specifically distinct from A. Bidwelli, which has the leaflets seldom 

 I line long, and the pod, although unripe, already above 4 inches, and 

 marked with veins, which may possibly disappear when the pod is ripe. 

 — G. B.] 



Contributions to Organographic Botany. By Cheistopheb 

 Dbessee, Esq. Communicated by the Secretary. 



[Read April 1st, 1858.] 

 [Abstract.] 



Mr. Dresses passes successively under review the scales of the 

 leaf-buds, the bracts, the sepals, the petals, the stamens, and the 

 carpels of plants, with the view of showing that they are not, as 

 usually considered, metamorphosed leaves, but metamorphosed leaf- 

 stalks or petioles. 



In support of this view, in relation to the development of leaf- 

 buds, he enters into a detail of the structure of the Horse-chestnut, 

 the Sycamore, the "Walnut, the Cherry, the Currant, &c., but ad- 

 mits that in some instances, the Holly for example, the scales are 

 more obviously analogous to the lamina of the leaf. With regard to 

 bracts he instances Angelica officinalis and Salvia fulgens, in the 

 latter of which he particularly calls attention to certain monster 

 bracts and their venations, as aflTording clear evidence of their 

 petiolar origin. The cases adduced in proof of a similar origin in 

 the calycine leaves are, first, the abnormal development of one of 

 the sepals in Musscenda ; secondly, the frequent greater or less 

 development of foliola upon the margins of the sepal in roses, 

 which sepal consequently is to be regarded as equivalent to the 



