8 MONOCOTYLEDONEAE. 
tandreæ every species has either 4 (in a very few eases 5), or 2, 
perfect stamens: the only exception is perhaps Acanthonema. of 
which I have not been able to examine any sufficient number of 
flowers. The rudiments are never so far developped as to simulate 
perfect stamens or to cause a moments hesitation whether the 
example should be reckoned diandrons or tetrandrons. This simple 
distinction is thus absolute for each species of Cyrtandreæ, and is 
most convenient to work with. Further, by the foundation of the 
simple genus Didissandra (which splits off 7 didynamons species 
from the large diandrons genus Didymocarpus), I have been able to 
make every genus of Cyrtandreæ (without any wipe either dian- 
drous or 4- (very rarely 5-) androns. 
8 D. MATERIAL FOR THE PRESENT MONOGRAPH. 
1. Herbarium, Kew; which includes (among other things) herb. 
Wight and C.-B. Clarke. 
2. Museum Britannicum ; which includes the material worked by 
D. Don and R. Brown. 
3. Museum Linnæan Society: consisting of the herbaria of Wal- 
lich and Horsfield. 
4. Herbarium DC. The first part being the Prodromus Herbarium 
i. e, the exact material on which the Cyrtandraceæ of DC. Prodr. 9 
was founded; the second part being the material since accumulated, 
comprising (among other things) the Tahiti plants of Nadeaud. 
3. Herbarium Museum Lugduno-batavum (Leyden); containing 
many specimens of Blume, and the material of De Vriese. 
6. Herbarium Museum Rheno-Traject. (Utrecht), containing 
many of the types of Miquel. 
7. Herbarium Delessert (Geneva) containing (among other things) 
several species of Jack, authenticated by his hand. 
8. Herbarium Boissier (Geneva) containing a large quantity of 
finely preserved specimens and many types. of cultivated species. | 
