ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ■>■> 



water and hence the time elapsing before germination. The experiments 

 tended to show that it was not the diminished absorption of oxygen but 

 the decrease of water which affected germination. Different seeds 

 behaved differently under the influence of light. One experiment made 

 with Atrvphx seemed to indicate that when the seeds are placed in water, 

 there is an outward diffusion of some substance having the power of 

 retarding germination. 



The present work shows that, although there may be differences in 

 the stages of development, the adult plants obtained from the two kinds 

 of seeds are equally strong, and show no material difference in structure. 



General. 



Organisms in Nectaries.* — I. V. Schuster and V. Ulehla publish a 

 preliminary paper in connexion with their study of the organisms found 

 in nectar-secreting structures. They have examined 32 different species 

 of woody and herbaceous plants, and find that the presence of minute 

 fungi and bacteria is of extremely common occurrence. In 23 of the 

 plants examined the nectaries were infected with a yellow species of bac- 

 teria, also even more frequently with a yeast fungus typically found in 

 Lamium album. To a smaller extent red yeast fungi and torula species 

 were also found. Under special conditions, e.g. where there is a stigmatic 

 cavity, as in Viola tricolor or in the slimy buds of poplar, infection can 

 only be brought about by a single species, which is always present. This 

 circumstance, together with the fact that such common forms of mould 

 fungi as Mucor, Penicillium, Aspergillus, etc. are never found in nectar, 

 points to the conclusion that nectar is the habitat of various species of 

 specially adapted bacteria and yeast fungi. That the latter are not 

 parasitic or harmful is shown by the perfectly normal ripening of the 

 fruit and seed of infected flowers. 



CRYPTOGAMS. 



Pteridophyta. 



(By A. Gbpp, M.A., P.L.S.) 



Phylogenetic Studies of Ferns. | — F. 0. Bower finds in Metaxya 

 rostrata Presl. {Alsophila blechnoides Hook.), an interesting step in the 

 phylogeny of the Ferns — a more primitive member of the Cyatheaceae, 

 which provides evidence that the arborescent habit of the Cyatheacere is 

 secondary and derived. Metaxya is distinct from Alsophila in the fol- 

 lowing characters : — creeping habit, simple hairs (not scales), soleno- 

 stelic structure of axis, undivided leaf-trace, flat receptacle, simultaneous 

 origin of numerous sporangia, almost vertical annulus interrupted at 

 insertion of sporangial stalk. It holds a similar independent position 

 to that of Lophosoria. Bower discusses the value of the point of origin 

 of the sorus as a constant systematic character, and divides the lepto- 

 sporangiate ferns into two series according as the sori originate from the 



* Ber. Deutsch. Bot. GeselL, xxxi. (1913) pp. 129-39 (1 pi.), 

 t Arm. of Bot., xxvii. (1913) pp. 443-77 (3 pis. and figs.). 



