52 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Distribution of Hairs on the Surface of the Stem.* — A. Daguillon 

 concludes as the result of an examination of the distribution of hairs on 

 the stems of various herbaceous plants, including species of Veronica, 

 Stellaria, and other members of the order Caryophyllacete, that in some 

 herbaceous plants there exists a relation between the distribution of 

 hairs on a stem and its branching, the hairs being usually restricted to, 

 or more abundant at the portion above the axillary buds. 



Manual of Indian Timbers.f — J. S. Gamble has prepared a new and 

 revised edition of this work, which contains a short diagnosis of the 

 wood and bark characters of all the woody plants of British India, with 

 notes on the distribution of the species, their cultivation, and economic 

 use. The arrangement is a systematic one and follows that of Hooker's 

 Flora of British India. The plates represent cross sections of nearly one 

 hundred species. 



Reproductive. 



Lagochilus.J— R. Wagner discusses the morphological details of the 

 inflorescence in species of this eastern genus of Labiatse. 



Cause of Floral Zygomorphism.§ — L. Barsanti reviews the opinions 

 of Sprengel, De Candolle, Monquin-Tandon, Roeper, Dutrochet, Vochting, 

 Delpino, and others, on the cause of asymmetry in flowers, and expresses 

 his own conclusions, which are that flowers were actinomorphic at first ; 

 that by evolution some have become zygomorphic ; that such zygo- 

 morphism was caused by mechanical causes such as pressure, or by 

 conditions of light or gravity, or by a biological cause such as the visits 

 of fertilising insects ; that it gradually acquired stability and became 

 transmitted by heredity. 



Theory of the Petiole in the Flower. || — D. Clos returns to the 

 discussion of the morphology of the stamen, a subject which he has 

 treated in previous memoirs. He holds the view that in most cases the 

 filament of the stamen represents, in dichlamydeous flowers, the median 

 nerve of the sessile petal or the claw of the clawed petal ; and that the 

 anther is a distinct structure of special nature. He criticises adversely 

 the view adopted by many botanists that the filament is homologous 

 with the stalk, and the anther with the blade of a leaf. He points out 

 that there is no relation between the existence of filaments in the androe- 

 cium and of petioles in the leaves of the same species. Thus sessile 

 leaves and long filaments occur in numerous Caryophyllacege, Cruciferas, 

 Crassulaceae, and other families, while Aristolochia, Arum, and Dracun- 

 eulus supply examples of sessile anthers and long-petioled leaves. 



On the other hand, there is a striking resemblance between the 

 petals and the filaments in many species of different families both 



* Rev. Gen. de Bot, xiv. (1902) pp. 289-99 (5 figs, in text). 



t J. S. Gamble, 'A Manual of Indian Timbers: an account of the growth, dis- 

 tribution, and uses of the trees and shrubs of India and Ceylon, with descriptions of 

 their wood structure.' New and revised edition, London, Sampson Low & Co., xxvi. 

 and 856 pp. and 20 pis. 



X Verhandl. k. k. Zool.-bot. Gesell. Wien, lit. (1902) pp. 540-62 (11 figs, in text). 



§ Atti d. Soc. Toscana di Sci. Nat., xviii. (1902) pp. 126-41. 



II Mem. Acad. Sei. Toulouse, ser. 10, i. (1901) pp. 105-18. 



