1870.] Botany. 395 



tarics and the irregularity of the flower, but had not discovered the 

 reason of this connection. To speak of the tufts of hair-like papilke 

 which are often found on the pistil as collectors of pollen for the 

 purpose of the self-fertilization of the flower, is clearly erroneous ; 

 their position shows that their use is the very opposite, serving to 

 sweep the pollen out of the way in order to prevent it from reach- 

 ing the stigma. Instead of polls colledeurs, by which term they 

 are known in French manuals, poils expulseurs would be a better 

 name for them. The heads of flowers of the order Composite 

 usually begin to expand at the circumference, the expansion then 

 extending to the centre. As a general rule the anthers are ripe be- 

 fore the stigmas (protandry of Hildebrand) ; the pollen, therefore, 

 of the inner flowers fertilizes the pistil of the outer flowers ; hence 

 the outer flowers of the ray are generally destitute of stamens. Dr. 

 Ogle finds that in Papilionaceee cross-fertilization is the rule ; and 

 that the peculiar form of the stamens in Erica, Vaccinium, Arbutus, 

 and other genera of the same order, contributes to this end. 



Fertilization of Ferns. — Dr. E. Strasburger contributes a paper 

 on this subject to Pringsheim's 'Jahrbuch fur wissenschaftliche 

 Botanik.' He commences the account of his experiments by tracing 

 the development of the antheridia, or cells which produce the sper- 

 matozoids, from their earliest condition, and states that the growth 

 of their lateral cells presents the first example in the vegetable 

 kingdom of annular cell-formation by division. The new twin cells, 

 a central cell and the annular lateral cells, are distinguished from 

 ordinary cells by the differences of their contents, the inner one 

 being stuffed with granular protoplasm, the outer ones containing 

 at first an almost colourless sap, with a single scarcely discernible 

 nucleus, and a few scattered grains of chlorophyll. After escaping 

 from the antheridium, the spermatozoids, corresponding to the 

 pollen of flowering plants, enter into the central cell of the arche- 

 gonium, or female organ, by a peculiar twisting motion, and there 

 meet with and fertilize the germ. A large number of the sperma- 

 tozoids will enter a single cell, forming a kind of chain, but fertili- 

 zation appears capable of being effected by one only. 



Turning of Flamts towards the Light. — M. Duchartre con- 

 tributes to a recent number of the * Comptes Eendus ' an account 

 of a remarkable growth of fungi in a garden at Meudon (Seine et 

 Oise). They were found growing in a hollow place beneath a 

 reservoir kept constantly full of water, in perfect darkness, but in 

 a comparatively high temperature. At the end of September, on 

 the lower surface of this reservoir were found more than 500 indi- 

 viduals of a small Agaric belonging to the genus Coprinus. They 

 were all towards the southern part, springing from the roof of the 

 cavity, with their head downwards. The stem of every individual 

 had departed from the vertical by an angle of at least 30°, their 



VOL. VII. 2 E 



