454 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and tbo species is tberoforc functionally dimorphic. In Averrhoa also 

 tho dimorphic is derived from the trimorphic structure by the dis- 

 appearance of the inner row of stamens. In RubiaceaD .and other 

 instances it appears to have a different origin. 



Species of Cassia have been described by H. Miiller as having styles 

 bending either to the right or left, and this he believed to be a contrivance 

 for promoting cross-fortilization. Herr Burck adduces tho reasons which 

 have led him to an opposite conclusion, that the arrangement favours 

 self-fertilization, and renders cross-fertilization almost impossible. 



Fertilization of Calopogon parviflorus.* — Mr. C. Robertson de- 

 scribes tho fertilization of Calopogon parviflorus Lindl., very common in 

 the pine-barrens of Florida. Small bees (Andrenidfle), approaching the 

 flower in front, light upon the crest, when the labellum bends suddenly, 

 so that tho dorsal surface of the insect comes down upon the column. 

 The broad, slightly upturned wings of the column keep the body from 

 passing to either side, and so require it to slip off the end. In doing this 

 the body strikes the stigma, and becomes smeared with viscid matter. 

 As the body slips off the end of the column the exposed ends of the 

 pollinia strike the part which is smeared with viscid matter from the 

 stigma, and the pollinia are drawn out and cemented to the exact spot 

 which struck the stigma in the first place. When the insect visits 

 another flower, the part to which the pollen is glued comes down upon 

 the stigma. 



Pollination of Alpine Plants.f — Herr C. Lindman describes the con- 

 trivances for promoting pollination in a number of plants from the 

 Scandinavian Alps. They include species adapted for self- and others 

 adapted for cross-pollination. 



Pollination of Silene inflata.J — Herr P. Magnus has observed that, 

 while in the neighbourhood of Berlin this species is polygamous and 

 trioccious (the hermaphrodite plants strongly proterandrous), at high 

 altitudes near Zermatt it is always gyno-dicecious, with inconspicuous 

 female and more conspicuous proterandrous hermaphrodite flowers. In 

 the latter the corolla is very fully developed, and projects far out of the 

 ventricose calyx, the flowers standing on long stalks. In the former the 

 corolla scarcely projects beyond the calyx ; the rudimentary stamens are 

 sometimes petaloid. All the plants bore well-developed capsules with 

 seeds, and the flowers must obviously have been pollinated by the agency 

 of insects. 



(2) Nutrition and Growth (including 1 Movements of Fluids). 



Physiological Oxidation in the Protoplasm. § — Herr W. Detmer 

 maintains that the oxidation of difficultly oxidizable substances, such as 

 sugar, which goes on in every living cell, is a process dependent on the 

 vitality of the protoplasm in the living cell, and he proposes for it the 

 term " physiological oxidation." In dead parts of plants experimented 

 on immediately after death, he finds that no respiration or combustion of 

 carbon takes place. The contrary conclusion of Eeinke || he attributes to 



* Bot. Gazette, xii. (1887) pp. 288-91. 



t Bot. Sallsk. Stockholm, May 4, 1887. See Bot. Centralbl., xxxiii. (1888) p. 58. 

 \ Ber. Hauptvers. Bot. Ver. Prov. Brandenburg, June 5, 1887. See Bot. 

 Centralbl., xxxiii. (1888) p. 136. 



§ Bot. Ztg., xlvi. (1888) pp. 39-45. || Sec this Journal, ante, p. 88. 



