582 TRANS. ST. LOUIS ACAD. SCIENCE. 



Southwestern New Mex co the large paniculate Agave Parryi 

 so loaded with this liquid that it actually rained on him when 

 he knocked on the stalk, or when the wind shook the panicle. 

 South European botanists, who have numerous cultivated species 

 and especially the naturalized A. Americana at their disposal, 

 are in a position to investigate and experiment upon this curious 

 physiological fact. Our A. Virginica exudes only a small quan- 

 tity o honey in the base of the tube, but nothing like such a 

 watery abundance. 



Explanation of Plate IV. 



Fig. I. Diagram of the flower. Three exterior lobes of the perigon cover 

 the thin margins of the 3 interior ones ; 6 stamens opposed to the 

 lobes ; 3 carpels opposed to the 3 exterior lobes, each with two series 

 of ovules ; in the centre the stigma, its 3 lobes alternating with the 

 carpels. 



Fig. 2. Top of the flower-bud, showing one interior between two exterior 

 lobes. 



Fig. 3. The same, inside, exhibiting the broader hood of the inner lobe 

 between the longer and narrower outer ones, all of them downy below 

 the tip. 



Fig. 4. An opening bud in the forenoon of the first day; the filaments 

 begin to straighten, raising the anthers, apparently in irregular order, 

 above the perigon ; style quite short. 



Fig. 5. Section of the same, with style and filaments cut off"; the perigon 

 is seen in full development before it begins to wither; insertion of the 

 filaments in the middle of the tube, the inner one slightly lower than 

 the outer ones. 



Fig. 6. Flower fully open on the first evening : filaments straight; anthers 

 opening at the upper and lower end; style not yet of the length of 

 the filaments. 



Fig. 7. Flower on the third day : anthers and perigon shrivelling, fila- 

 ments yet erect; style of nearly full length; stigma yet closed. 



Fig. 8. Flower on the fifth day : perigon and filaments wilted ; style fully 

 developed, stigmatic lobes separated and bearing a large drop of glu- 

 tinous liquor. — All these figures in natural size. 



Fig. y. Stigma closed. 



Fig. 10. Same with expanded lobes, both magnified 4 times. 



Fig. II. Pollen grains magnified 100 times : one intact, slightly elliptic; 

 the other, developing its tube and somewhat contracted. 



