ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 605 



only Lathrcea squamaria. Group IV. includes Cuscuta and Gassytha, 

 Group V. the Orobanchacese, Group VI. Raffiesia and allied genera, 

 while Group VII.. represented by the Balanophoracese, shows the highest 

 degree of modification. The method of parasitism of each group is 

 shared equally by every member, and this method is distinct from that 

 of each of the other groups. All parasitic habits and structures appear 

 to be inherited. None of the types show any tendency to revert to 

 normal conditions, and although the fruit and flowers show that these 

 parasites were originally normal Phanerogams, no transitional types 

 can be discovered. The author assumes that phanerogamic parasites 

 have originated " by sudden and aggregate mutation from normal 

 Phanerogams." 



Ultramicroscopic Organisms.* — H. Molisch publishes the results of 

 his observations made in the attempt to discover ultramicroscopic 

 organisms. So far no such bodies have been made out with certainty, 

 and the author is of the opinion that if they do exist, they are of little 

 importance and relatively few. All bodies previously thought to belong 

 to this class have proved, on further investigation, to be colonies of 

 minute bacteria, and the present results confirm the opinion put forward 

 by Errera, that any existing ultramicrobes cannot be much smaller than 

 the smallest known organisms. Investigations made upon the mosaic 

 disease of tobacco and the chlorosis of the Malvaceae, make it probable 

 that diseases hitherto ascribed to microbes are due to the toxic action of 

 some assimilation-product. 



CRYPTOGAMS. 



Pteridophyta. 



(By A. Gepp, M.A., F.L.S.) 



Effect of Light upon Spore-germination.f — A. C. Life describes 

 the effect of light upon the germination of spores and the gametophyte 

 of ferns. The spores of Alsophila australis germinated a year after 

 collection, those of other ferns germinated as soon as they were dry. 

 Ordinarily the spores do not germinate in darkness. At temperatures 

 above that of ordinary rooms the spores of Alsophila and Aneimia would 

 not germinate. Germination was best in light of medium intensity, 

 weaker light inducing filamentous or ribbon-like prothallia, while strong 

 light induced heart-shaped prothallia. Strong light led to the production 

 of only archegonia in Alsophila, but of both sex-organs in the other 

 species. Weak light favours the production of antheridia and inhibits 

 that of archegonia. 



Ophioglossum simplex.^ — P. 0. Bower publishes a further note on 

 Ophioglossum simplex Ridley, a unique species from Sumatra described by 



* Bot. Zeit., lxvi. (190S) pp. 131-9. 



t Ann. Rep. Mo. Bot. Gard., xix. (1907) pp. 109-22. See also Bot. Gazette, 

 xlv. (1908) p. 421. X Ann. of Bot., xxii. (1908) pp. 327-8. 



