426 SUMMARY OF CURRENT RESEARCHES RELATING TO 



root-hairs and thus establishes a close relation between the orchid and 

 its support. The author suggests that this morphological connection is 

 the expression of a symbiotic association, and that the fungal hyphte 

 convey nutritive matter to the orchid. He also assumes that similar 

 facts will be discovered in connection with other orchids, and also in 

 other climbing plants. 



Resistance of Certain Seeds to the Action of Absolute Alcohol.* 

 P. Becquerel concludes as the result of experiments that whereas the 

 testa of a damp seed allows osmosis and is permeable to absolute 

 alcohol, when it has been dried to a certain degree osmosis does not 

 take place, and the seed-coat is quite impermeable to the anhydrous 

 liquid. Consequently in this condition, if the coat form a complete 

 covering, anhydrous poisons, such as bichloride of mercury, when 

 added to the absolute alcohol, have no effect on the power of 

 germination. 



Permeability to Gases of Certain Dried Seeds.f — The same 

 author, experimenting with seeds of pea, lupin and Gleditschia, showed 

 that the dried seeds are impermeable to dry air and dry carbonic acid 

 gas, but permeable when these gases are charged with water vapour. 

 These results explain the absence of all respiratory interchange of gases 

 when quite dry seeds are plunged into a rigorously anhydrous atmo- 

 sphere. But we cannot conclude that all the phenomena of respiration 

 in the seed are at a standstill. The plantlet, enclosed in its dry testa as. 

 in a hermetically sealed chamber, may respire imperceptibly at the 

 expense of oxygen stored in its cells. As soon as the reserve gas is 

 used up or a sufficiently large amount of carbonic acid gas is produced r 

 the embryo must die either of inanition or by asphyxiation. This will 

 explain the marked decline in germinating power which has always been 

 observed in such experiments which have lasted from 7 to 16 years, for 

 instance, those of Jodin and Giglioli. 



Niclocx, M. — Sur le pouvoir saponifiant de la grain de ricin. (On the saponifying 

 property of the castor-oil seed.) 



[The author shows that the active lipolytic suhstance in the seed is the 

 cytoplasm, to tbe exclusion of all the other elements in the seed.] 



Comptes Hendus, cxxxviii. (1904) pp. 1175-7. 



General. 



Pollination of the Primrose.:}: — E. Bell, the author, under the 

 nom de guerre " A Field Naturalist," of " The Primrose and Darwinism," 

 in which Darwin's theories on the relation between heterostyly and 

 cross-pollination by insects were attacked at some length, criticises some 

 remarks by Prof. Weiss in a pamphlet on the "Pollination of the 

 Primrose." He maintains that of the very few insects which have 

 been observed visiting the flowers of the primrose, the proboscis is with 

 two exceptions too short to reach the nectar. The visits of the latter 

 are, however, so extremely rare, as to preclude their efficiency as agents 



* Comptes Rendus, cxxxviii. (1904) pp. 1179-81. 



t Tom. cit., pp. 1347-9. 



j Nature Notts, xv. (April 1904) pp. 63-9. 



