624 Gironicles of Science. [Oct., 



Fertilization of Gi-aminex. — M. Bidard lias hem. observing the 

 fertilization of grasses. He states that their pollen does not exhibit 

 any trace of poUen-tnbes, and that self-fertihzation takes place before 

 the anthers are extended beyond the perigone. The fovilla is itself 

 absorbed from the pollen after it falls on the stigma through the 

 thread-like tubes which perforate it. There exist in gi-asses two 

 principal phenomena which are only known as belonging to this 

 family, — the elongation of the filaments and their extrusion from 

 the perigone after fertihzation has taken place, and the fecundation 

 by perforation of the pollen. The heat of the breath or a ray of 

 sunshine is sufficient to bring about the phenomena of fecundation ; 

 and the natural hybridization of grasses is impossible, owing to the 

 exact closure of the chamber containing the fecundating organ. 



Fertllizcdion of Salvia. — A contribution towards the investi- 

 gation of the phenomena attending the impregnation of plants has 

 been made in the case of the genus Salvia, affording a striking 

 instance of the natural tendency towards cross-fertilization which 

 Mr. Darwin has pointed out. The two perfect stamens of Salvia 

 contain each two anther-cells at the opposite ends of a connective 

 which is longer than the filament itself. The arm of the connective 

 to which the upper anther-cell is attached is longer than that which 

 supports the lower anther-cell, this latter being in some species 

 entirely, in others partially, destitute of pollen. The lower anther- 

 cell projects far into the mouth of the corolla, so that when the 

 flower is visited by the bees, which frequent it very freely, the 

 insect necessarily pushes it aside, and causes the extremely mobile 

 connective to rotate ; the upper anther-cells thus emerge from the 

 hooded receptacle in which they are hidden, so as to bring their 

 dehiscing surfaces into contact with the bee, one on either side. 

 The stigmas are not ripe till a considerably later period than the 

 anthers, and the style being prolonged much beyond the upper 

 anther-cells, these cannot in their rotation strike against the stig- 

 mas, nor does the bee strike them in retiring from the flower. 

 At a later period of development, however, the style becomes bent 

 down, so that the stigmas block up the entrance into the mouth of 

 the corolla, and it is only at this period that the stigmatic surface 

 becomes fully developed. When a bee laden with pollen enters a* 

 flower in which the style has assumed this position, it caimot fail to 

 rub its back against the stigmatic surface, and thus secure the ferti- 

 lization of the flower. Tliis structure has been observed, with shght 

 modifications, in Salvia ojicimdis, glutinosa, pratensis, Sclarea, 

 and some other species. 



Effects of Sinol'e on Vegetation. — Mr. E. Green, gardener to the 

 Right Hon. J. W. Patten, M.P., of Warrington Hall, read at the 

 Manchester Congress an article on this sultject, which contains some 

 useful hints for dwellers in towns. During the last twenty years 



