72 SUMMARY OF CURRENT RESEARCHES RELATING TO 



monotype, and one of the most remarkable of the endemic genera of 

 Chinese trees. It was discovered more than thirty years ago by the Abbe 

 David near Moupin, in the province of Szechuen, but a recent supply 

 of fresh seeds has rendered possible the study of the germination. The 

 fruit is drupe-like ; the hard bony endocarp intrudes between the six to 

 ten one-seeded cells to the axis with which it unites. After the decay 

 of the fleshy coat, the fruit opens by the separation of the upper portion 

 (one-half to two-thirds) of the back of each carpel in the form of a 

 valve or shutter. Usually only about half the number of the ovules 

 are fertilised and develop, sometimes only one. The solitary pendulous 

 seeds are not released by the falling away of the dorsal valves, but held 

 fast until the seedling has reached a considerable development. The 

 straight embryo has a pair of flat leafly cotyledons, and is imbedded in 

 endosperm. After the dehiscence of the dorsal valves of the carpels, 

 the radicles of as many seeds as are present in the fruit emerge simul- 

 taneously, the cotyledons elongate rapidly, the axis of the plantlet is 

 •carried out of the testa, and the cotyledons after absorbing the endo- 

 sperm free themselves, and form the first green leaves of the plant. An 

 •opposite pair of foliage-leaves is developed at right angles to the cotyle- 

 dons, while the succeeding leaves are alternate. The writer suggests that 

 in a cluster of seedlings, developing thus from one fruit, there is a greater 

 chance of partial escape from phytophagous organisms than there is for 

 solitary individuals. Another point of interest is the presence of buds 

 in the axils of the cotyledons, which may serve to ensure the develop- 

 ment of the plant if the plumule is injured or destroyed. 



Davidia is usually placed in the Cornaceae, next to Nyssa, a genus 

 of Asiatic and North American trees, which it resembles in some 

 particulars, but from which it differs greatly in appearance and floral 

 structure. 



Synanthy in Lonicera.* — E. A. N. Arber gives a detailed account 

 of the cases of synanthy which occur in the Xylosteum section of this 

 genus. This, the largest of the three sections into which the genus has 

 been divided, contains more than seventy species, which are mainly erect 

 shrubs. It is widely distributed in the northern hemisphere, but its 

 chief centre is eastern Asia ; several species are alpines in the mountains 

 of southern and eastern Europe. Two different types of synanthy are 

 represented. One, which is distinguished as true synanthy, is effected 

 by the partial or complete fusion of the receptacular walls of the inferior 

 ovaries or fruits, and the bracteoles play no part in its formation. 

 Lonicera xylosteum, a doubtful British plant, is an example of an in- 

 complete union ; L. alpigma may serve as the type of the somewhat 

 more numerous cases in which the synanthy is complete, and where the 

 resulting fruit is a false berry, the pericarp being formed from the walls 

 of the two ovaries. In many species the pistils are enveloped by a 

 bracteolar sheath, which as a rule plays no part in the formation of the 

 fruit, but in Lonicera crrrulea a false synanthy is effected by the union 

 of the two pistils in certain planes with the bracteolar sheath, the pistils 

 themselves remaining quite free from one another. The fruit is a 



* Journ. Linn. Soc, xxxvi. Bot. (1903) pp. 463-74 (3 figs, in text). 



