natural Family of Plants called Composite. — 87 
— formerly quoted, stated this to be valvular, that is, 
having the margins of the segments applied to each other and 
dehiscing like the valves of a capsule. As I have remarked in 
the same place that this estivation exists in several other fami- 
lies, it is rather surprising that M. Cassini, in the abstract of his 
third memoir given in the Nouveau Bulletin des Sciences for last 
October, should seem to consider this characteras peculiar to Com- 
positæ*. It appears also- that he is not aware of any exception to 
itin the class. I have however, in a different part of the same essay, 
noticed one exception existing in Chuquiraga, and I have since 
found another in Corymbium. In both these genera the æstivation 
is induplicate, that is, the margins of the segments are doubled in, 
so that in the unexpanded state none of them are visible. I have 
* 
* Since this paper was read, M. Cassini has published his memoir (in the Journal de 
Physique for February 1816), in which he states the same æstivation to exist in certain 
other families, namely, Campanulaceæ, Lobeliaceæ, and Rubiacee. This observation, if 
applied to the whole of these families, as is evidently the author's intention, is correct only 
with respect to Campanulacez, from which I have separated Stylidee as a distinct order, 
partly, as I have stated, on account of its imbricate æstivation. In a considerable part of the 
Lobeliacez of Jussieu, which includes my Goodenoviæ, the æstivation is not valvular but indu- 
plicate: and though in Rubiaceæ the valvular mode is very general, there are many remark- 
able exceptions to it, as Gardenia, Ixora, Pavetta, Coffea, and several other genera, where 
it is unilaterally and obliquely imbricate, as in most of the Apocineæ, with which Linneus 
united them under the name of Contortæ, derived from this very circumstance. On this 
subject I may be allowed further to remark, that M. Cassini, who in the memoir now cited 
has repeatedly asserted his claim to the priority of the observation on the disposition of 
vessels in the corolla, has in treating of its æstivation omitted to notice what had been 
already published respecting it in my essay above quoted, where I conclude he must have 
seen my observation, as he refers to the sentence containing it. The æstivation of corolla 
in Composita is also noticed in the observations on Brunonia, contained in my Prodromus: 
Flore Nove Hollandie, which I suppose he has not seen: I may therefore, for the 
general importance of æstivation of calyx and corolla in affording characters both for Orders 
and Genera, refer him to almost every page of the same work, and to its preface, for an 
observation on the degree of attention that had been previously paid to this point of structure, 
which will enable him to correct in some measure his own remark on the subject. : 
in 
