262 OBSERVATIONS ON THE NATURAL FAMILY
with those, and which I considered secondary in this order, though they occupy the place of the primary vessels in other families : and it is this inverted disposition, indicated in the greater part of the class by the primary being the only vessels existing, which I have considered as of material importance in determining the limits of Compositae, though by no means as affording an essential practical character for the whole class.
In the passage quoted from M. Cassini (the only one I can find relative to the subject in the memoir in which it occurs), the existence of five nerves or vessels in the tube of the corolla, alternating w T ith its latinise, is stated, but their division and disposition in the laciniae are not noticed ; it is at the same time to be inferred from the terms of the passage, that no other vessels exist in the tube of the corolla : and it is equally evident that, so far from announcing this disposition of vessels as a discovery, or peculiar to the order, the author rather considers it either as a fact already known, or as the usual structure. That M .. Cassini was not then aware of the importance of the fact which he had imperfectly stated, appears likewise from his having, many months after his memoir was read, and at a time when he says he had finished his analysis of the corolla, proposed a name for the class, taken from a sup- posed peculiarity in the structure of the filament, a name which he is now inclined to abandon for one derived from the disposition of vessels in the corolla.
so] Since my attention has been again turned to the sub- ject, I have endeavoured to collect all that has been observed on the nerves or vessels of the corolla of Compositae, a brief account of which may be not altogether without interest.
The earliest notice I have been able to find is contained in a passage (in page 170) of Grew's Anatomy of Plants, where, in speaking of syngenesious flosculi, he says, " they are frequently ridged, or as it were hem'd like the edge of a band." And his figure of a magnified floret of the common Marigold, in tab. 61, gives a tolerable idea of the marginal vessels of its lacunae. Grew however takes no
�� �
