f)40 SUMMARY OF CIMUtKNT RFSFAKCHFS RELATING TO 



ventrality of the branch, and the asymmetry of the leaves is a correlation 

 of the same condition. The dorsiventrality of the branches appears bo 

 be due bo unequal distribution of food-material at the growing-point : 

 when the food-supply is equally distributed the dorsiventrality gives 

 place to a radial arrangement. Similar statements hold good for 

 flowers Axillary buds cause asymmetry of the inner halves of the 

 subtending leaves. 



'S 



Monocotyledonous Characters in the Polycarpeae.* — R. E. Fries 

 has examined many plants belonging to the Polycarpeae, and while 

 finding no instances of fused cotyledons in the Ranunculaceae, Lardiza- 

 balacea?, Berberidaceas, Menispermaceas. Magnoliaceae, Calycanthaceae, 

 Myristicaceaa, Moniniiacese and Lauraceae, has found numerous instances 

 of fused first leaves in vegetative-buds, flower-buds, and in the in- 

 florescences of the Nymphasacefe. The author points out that this 

 monocotyledonous character is also commonly found in the Anonaceae 

 and Aristolochiacea?, and that there are many reasons for classifying 

 these two families in the same group as the Nymphaaacea?. Many 

 writers regard the Aristolochiaceaa as descendants of extinct Anonaceas, 

 and such a widely spread (though hitherto little noticed) common 

 character cannot be a coincidence, but seems to point to a relationship 

 between the three families, and also to a connexion with the Mono- 

 cotyledons. The present paper is to be followed by another dealing 

 with this point in special reference to the Anonaceae. 



Reproductive. 



Morphology of Diospyros.j — S. M. Hague has studied the morphology 

 of the flowers of Diospyros virginiana, and the following are the chief 

 results of her work. The flowers are formed on young shoots, the 

 order being — a pair of bracts, calyx, corolla, stamens, and pistil. The 

 anatropous ovule has two integuments and contains four megaspores, 

 the ehalazal one becoming the embryo-sac. The latter is small at the 

 eight-ceded stage, and rests upon a stalk-like portion of the nucellus ; 

 it is surrounded by a tapetal layer formed from the inner integument. 

 There is little evidence of pollination and none of fertilization, which 

 probably accounts for the seedless fruit. After the flowers fall the 

 ovule enlarges and endosperm rapidly forms until the embryo-sac is 

 full ; the embryo is late in appearing, and a tendency to variation is 

 seen in freak embryos and polyembryony. Pollen-mother-cells are 

 found a week before the older flowers are open ; they are large and 

 show difference in size, while frequently only one nucleus can be 

 distinguished. 



" Hypanth " of the Rosacea?.:}: — A. Hillmann has investigated the 

 floral structure in the Rosacea? in order to discover the nature of the 

 "hypanth." With this object the author has given special attention to 



* Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 292-301 (6 figs.). 



t Bot. Gaz., lii. (1911) pp. 34-45 (3 pis.). 



\ Bot. Centralbl., xxvi. 3 (1910) pp. 377-421 (7 figs.). 



