AGEICULTURAL BOTANY. 527 



carbon dioxid. The increase amounted to considerably more than could be 

 accounted for by the leuciu that had 'disappeared. 



Studies on iron-storing Hyphomycetes, R. Lieske (JahrJ). Wiss. Bot. 

 [Pringsheim'], 50 {1911), No. 3, pp. 32S-354, figs. 3; ahs. in Mijcol. Centbl., 1 

 (1912), No. 1, p. 20).—ThQ author was led by numerous observations on the 

 rapid growth of certain fungi and bacteria in iron solutions to undertake a 

 study of certain forms, in particular of one closely allied morphologically with 

 Citromyces pfefferianus but showing such physiological divergences as led to its 

 classification as a separate species to which he gave the name C. siderophilus. 

 This was investigated in regard to its behavior in connection with iron solu- 

 tions added to its culture medium, as were also the fungi Aspergillus niger, 

 Penicilliuni glaucuni, C. glaber, C. pfefferianus, and several iron bacteria. 



Numerous fungi living in iron-containing waters are found to store in their 

 cells, as do the iron bacteria, a considerable amount of hydrated oxid of iron. 

 Most of these are closely allied morphologically with C. pfefferiamts, but physio- 

 logically they differ widely therefrom. C. siderophilus thrives in an iron-free 

 culture medium as do the mold fungi, but the addition of 0.5 per cent sulphate 

 of iron causes a notable increase of weight in case of this fungus, while other 

 mold fungi are checked in growth by such addition. C. siderophilus shows a 

 particular resistance to the poisonous influence of zinc sulphate. Iron protoxid 

 salts cause no chemically poisonous effect on C. siderophilus but a significant 

 promotion of growth. Iron oxid salts are as poisonous to this as to the other 

 fungi. The growth-promoting agent is the ferro-ion, the growth-checking one 

 the ferri-ion. Nondissociating iron salts have no marked influence on growth. 



With the presence of iron protoxid in the nutritive solution, the fungus is 

 better able to utilize its carbon supply and can thus flourish in a poorer culture 

 medium. The incrustation of hyphse with iron is not dependent upon the 

 growth-producing influence of the protoxid, but upon the nature or constitution 

 of the carbon source. It is supposed that the iron-storing bacteria play an 

 essential part in the formation of beds of bog-iron ore. 



On the presence of arbutin in leaves of Grevillea robusta, E. Bourquelot 

 and Mile. A. Fichtenholz (Compt. Rend. Acad. Sci. [Paris], 154 (.1912), No. 

 17, pp. 1106-1108). — Since their discovery and investigation of arbutin in species 

 of Pyrus (E. S. R., 25, p. 27 ; 26, p. 327), the authors have extended their studies 

 to other genera and they state that they have been able to identify this glucosid 

 in leaves of G. robusta. 



Wood coloring' in living spruce, C. von Tubeuf (Naturiv. Ztschr. Forst u. 

 Landw., 9 (1911), No. 6, pp. 273-276, figs. 2; abs. in Bot. Centbl., 119 (1912), No. 

 5, p. 9S). — ^Au account is given of the author's studies on 3 specimens of 

 spruce, in which the sapwood from roots to topmost twigs, with the exception 

 of the youngest annual rings, showed a blue-black color on being freshly cut, 

 becoming darker for a few days and afterwards remaining unchanged. Micro- 

 scopic investigations failed to reveal the presence of any organism or any indi- 

 cation of other abnormality. Microchemical tests seemed to show that the 

 coloring was due to impregnation with tannate of iron. This, however, did not 

 seem to interfere with the free passage of water, etc. Root injuries, it is 

 thought, may be a contributing cause. Further investigations are contemplated 

 to induce artificially, if possible, coloration, which appears to be entirely harm- 

 less to the living wood. 



The influence of sea water on the distribution of plants, J. W. Haesh- 

 berger (Proc. Amer. Phil. Soc, 50 (1911), No. 201, pp. 457-496, pis. 3, figs. 7). — 

 A study was made of the salt content of marsh soils and estuarine waters in 

 their relation to plant distribution along the coast of New Jersey. The hy- 



