118 Historical Sketch of Improvements in [Aug. 



under the name of Calycereae (or Boopidese, as it has been since 

 called by Cassini), intermediate between the compositaj and dip- 

 saceae; differing from the former by the pendulous ovulum and 

 albumen enclosing the embryo, the radicle pointing to the apex 

 of the pericarpiuin, the accretion of the base of the style with 

 the tube of the corolla, the absence of the epigynous disk or nec- 

 tarium, and the longitudinal division of each cell of the anthers 

 by a receptaculum pollinis ; and from the latter by the vascular 

 structure and valvular aestivation of the corolla, the aestivation, 

 insertion, and connexion of the antherae, in the absence of the 

 partial involucrum, and in having alternate leaves. Linn. Trans. 

 Compositce. — Mr. R. Brown has inserted in the Linn. Tr. xii. a 

 number of observations on these plants, to which he has appended 

 several original observations upon various other plants : in 

 which he shows, 1 . The aestivation of the compositae is valvular, 

 except in the genera chuquiraga and corymbium, in which it is 

 induplicate. 2. The fasciculi of vessels, or nerves, which at their 

 origin are generally equal in number to the divisions of the co- 

 rolla, instead of being placed opposite to these divisions, and 

 passing through their axes as in other plants, alternate with them; 

 each of the vessels at the top of the tube dividing into two equal 

 branches, running parallel to and near the margin of the corre- 

 sponding laciniae, within whose apices they unite. In several 

 genera other vessels occur alternating with the primary, and oc- 

 cupying the axes of the laciniae : in some cases these secondary 

 vessels are most distinct in the laciniae, and become fainter as 

 they descend the tube, so that they might be regarded as recur- 

 rent, originating from the united apices of the primary branches, 

 only that in other cases they arc equally distinct at the bottom of 

 the tube. 3. The pollen of the cichoraceoe is a regular icosa- 

 hedron, except that of geropogon glabrum, in which it is a re- 

 gular dodecahedron ; these angular figures are not observed in 

 any other family of plants; the pollen of the corymbifcrae and 

 carduaceae is spherical or oval. 4. The branches of the style 

 and stigmata are anterior and posterior. 5. The ovarium con- 

 tains two slender cords originating from opposite points of the 

 base of the ovulum, or of its footstalk, which run u)5, and are 

 more or less connected with the lateral parietes of the ovarium, 

 until they unite at the top of its cavity, immediately under the 

 style, between which and the ovulum a connexion is thus formed. 

 Now as the pistil, or female organ of all phenogamous plants, 

 seems formed on the plan of a circular series of polyspermous 

 legumens, or folliculi, whose seeds are disposed in a double series, 

 the legumens corresponding in number to that of the parts of 

 the calyx or corolla ; of course the ovary of the compositai is 

 composed of two confluent ovaria. 6. In a simple spike the ex- 



f)ansion of the fk)wers is generally ascendent, that is, the 

 ower open first; but i)i a compound spike, the expansion of 

 the partial spikes is generally ascendent, and that of the 



