556 MR. W. B. HEMSLEY ON THE GERMINATION 
Puate 18. 
Figs. 1-3, Staurastrum pseudopelagicum, sp.n. x 470. 
4. » paradoxum, Meyen, forma. xX 470. 
5. ” » forma. x 470. 
6, 7. ” ” var. cingulum, var. n. 6, x 470; 
7, X 384. 
8. ” sexangulare, Rabenh., var. swpernumeraria, var. Nn. 
x 470. 
9, ” Arachne, Ralfs, var. curvatum, var.n. X 384. 
10. ” gracile, Ralfs, forma. x 470. 
On the Germination of the Seeds of Davidia involucrata, Baill. 
By W. Borrrya Hemstey, F.R.S., F.L.S., Keeper of the 
Herbarium and Library, Royal Botanic Gardens, Kew. 
(Pxate 19.) 
[Read 18th June, 1903. } 
Davipra is one of the most remarkable of the endemic genera of 
the trees of China. It is a monotype with foliage strongly 
resembling that of a lime-tree and an inflorescence resembling 
no other. 
The flowers are borne in globose, solitary heads about an inch 
in diameter on axillary peduncles, two or three inches long, and 
bearing two oblong, nearly opposite, pure white, ieaf-like bracts, 
four to six inches long. 
The inflorescence consists of a number of male flowers, with- 
out any perianth, encircling a solitary, obliquely inserted female 
flower, which bears five rudimentary stamens around the ovary 
near the top. Or sometimes the inflorescence consists of male 
flowers alone; sometimes of a solitary hermaphrodite flower. 
The ellipsoid fruit, about an inch and a half in length, is 
drupoid in composition and is obliquely attached. 
The pericarp consists of a thin epicarp and mesocarp and a 
very hard, bony endocarp which intrudes between the six to ten 
1-seeded cells to the axis, with which it is consolidated. Both 
the dehiscence of the fruit and the germination of the seeds are 
of a highly curious character. After the decay of the outer 
layer of the pericarp, dehiscence takes place by the separation 
of the upper half, or sometimes as much as two-thirds, of the 
back of each carpel in the form of a valve or shutter. 
Usually only about half the ovules are fertilized and developed ; 
