29S TRANS. Sr. LOUIS ACAD. SCIENCE. 



species free from near its base, in otliers adnate up to the base 

 of the lobes (an important character which has often been neg- 

 lected) ; the outer stamens are usually placed a little higher than 

 the inner ones. In the bud the filaments are always doubled up,* 

 geniculate, and straighten out when the flower opens, and almost 

 always become much longer than the perigon ; in a few species 

 they do not exceed the length of the lobes. The filaments are 

 generally attenuated from a broader base and terminate in a thin 

 point, on which they bear the large and conspicuous linear,! near- 

 ly quadrangular, somewhat introrse, 4-celled, versatile anther, 

 attached near or a little below the middle ; m A. Virginica the 

 filaments are thickened upwards, almost clavate. The globose, 

 or elliptic, delicately reticulated pollen-cells have, on an average, 

 a diameter of 0.06 to mostly 0.08 or even o.ii mm. 



The ovary consists of three carpels, opposite the outer perigo- 

 nal lobes, forming three cells, n each o which two vertical rows 

 of flat, horizontal, anatropous ovules spring from the central pla- 

 centae. The stout, somewhat triangular, tubular style rises to the 

 height of the anthers and sometimes above them, but its length 

 is variable and does not seem to be always characteristic. The 

 stigmatic part is thickened, clavate, or somewhat capitate, and 

 is divided into three carinalj lobes, which at last open some- 

 what, or especially in the first section, expand horizontally, and 

 are often emarginate or even obcordate ; after expansion they (at 

 least in A. Virginica) exude a viscid liquid — whether stigmatic, 

 or only intended to allure insects, has not been ascertained. 



The flowers of Agave — I speak particularly of A. Virginica^ 

 the only one I have been able to observe in its developir.ent, but 

 I suspect that the same holds good in all the species — are ves- 

 pertine or nocturnal and proterandrous. They open late in the 

 afternoon or in the evening, and, while the filaments straighten 

 out and elongate, the anther-cells burst and emit the large pollen 

 grains, and on the following morning are found withering and 

 empty. The style at this period usually does not yet exceed 

 the perigon (in A. maculosa it is much shorter), and its lobes are 



* Even the short filaments oi A. maculosa are thus geniculate. (See p. 301. note.) 

 t The curved antliers spoken of in some descriptions can only refer to effete and with- 

 ing ones. 



X See page 293. note . 



