612 SUMMARY OF CURRENT RESEARCHES RELATING TO 



fact, certain berries, such as those of Atropa Belladonna ; but a greater 

 uuniber of the fleshy Solauaceous fruits belong to the second typo. 



Motion of rotating Winged Fruits and Seeds.* — Herr H. Dingier 

 finds that in the patli of winged fruits and seeds in falling to the ground 

 when there is a current of air, there is a double motion — a movement of 

 rotation of the body round its own axis, and a helicoid movement in 

 the opposite direction. He explains both these movements on the prin- 

 ciple of the motion of a top spun between the fingers. 



/3. PhysiologTT.f 

 (1) Reproduction and Germination. 



Pollination and Distribution of the Sexual Organs.^— Herr A. 



Schulz publishes the results of his observations on these points on a 

 very large number of si^ecies. The following arc some of the moro 

 general results at which he has arrived . - 



In the Silcnea3 there is a very strong tendency to uniscxuality and 

 dioecism ; the female are usually smaller than the male, and these again 

 than the hermaphrodite flowers. Among the latter proterandry is nearly 

 universal. The Alsinete produce, in addition to the ordinary herma- 

 phrodite, smaller female, but no male flowers ; the hermai^hrodite flowers 

 are often proterandrous, and usually can be fertilized only by external 

 assistance. Almost all Umbellifera^ have both hermaphrodite and male 

 flowers, either in the same umbel or not ; in the former case the marginal 

 flowers of the umbel are usually hermaphrodite, the inner flowers male ; 

 but some genera have a central hermai)hrodite flower. The herma- 

 phrodite flowers are in most cases so strongly proterandrous that self- 

 pollination is impossible, the stigmas often not arriving at maturity until 

 the stamens and even the petals have disappeared. Almost all Labiatae 

 have female in addition to the hermaphrodite flowers, and they are 

 usually much smaller ; the two kinds may occur on the same or on 

 different individuals, and in the former case in the same or in different 

 inflorescences. The hermaphrodite flowers are almost always strongly 

 proterandrous. 



Effect of Cross-fertilization on Inconspicuous Flowers. § — Miss Anna 

 Bateson gives the details of some experiments showing the effect of cross- 

 fertilization on inconspicuous flowers. The plants experimented on were 

 Senecio vulgaris, Capsella hursa-pastoris, and Stellaria media. In the 

 case of Senecio vidr/aris the crossed plants showed an advantage in 

 fecundity over the self- fertilized, the average number of seeds per 

 capitiilum of the cross-fertilized being to the average number per caj^i- 

 tulum of the self-fertilized as 100 to 73. With Capsella hursa-pastoris 

 the relation in the case of crossed to self-fertilized plants was as 100 to 

 96, and with Stellaria media as 100 to 95 ; thus it appears that incon- 

 spicuous flowers do benefit by a cross, though apparently in a less degree 

 than those adapted for self-fertilization. 



* Bcr. Deutsch. Bot. GeselL, v. (1887) pp. 4.30-4. 



t This subdivision coutains (1) Reproduction and Germination ; (2) Nutrition 

 and Growth (including Movements of Fluids) ; (3) Irritability ; and (4) Chemical 

 Changes (including; Respiration and Fermentation). 



X Uhlworm u. Hanlein's Biblioth. Bot., Heft 10, 104 pp. and 1 pi., Cassel, 1888. 



§ Ann. of Bot., i. (1888) pp. 255-Gl. 



