186 BOTANICAL GAZETTE [FEBRUARY 
for a source of energy and nutrition. The results of this investigation on Spiro- 
phyllum ferrugineum would make it appear that for certain of the iron bacteria 
the storage of iron is not brought about by mechanical means, as MOLIScH 
suggests. 
Using PFrEFFER’s phrase “chemosynthesis,” LresKE draws attention to the 
fact that CO, is chemosynthetically assimilated by certain other species of oxidi- 
zing bacteria, such as WINOGRADSKY’s nitrate and nitrite bacteria: those capable 
of transforming thiosulphates into tetrathionic and sulphuric acids; those 
splitting up H.O.; or those that are able to oxidize CH, and CO and u tilizing 
the carbon contained therein directly. He then is of the opinion that this 
particular iron bacterium, Spirophyllum ferrugineum, acts in an entirely similar 
way, inasmuch as from an elementary analysis of organisms grown in a fluid 
medium containing inorganic salts, metallic iron, and no other source of C 
other than that supplied indirectly by the action of CO. on the metallic iron 
(forming ferrous carbonate), he was able to prove a distinct increase in the 
content of the mass of bacterial filaments. LresxKE calculates that the quantity 
of ferric oxide that Spirophyllum ferrugineum must form from ferrous carbonate 
to gain one part of C is 750 parts, if roughly estimated in parallel to the require- 
ments of the nitrite bacteria. 
That this use of ferrous carbonate for the sole purpose of chemosynthesis 
of C applies to all iron bacteria is, as LIESKE states, questionable; but the 
fact that it now seems proved in the case of this particular iron bacterium 
lends new life to the hypothesis of WINoGRADSKy; and at the same time makes 
it necessary that new and more widespread study of the several species of 
iron bacteria be undertaken in a most ‘thorough manner.—Norman Macb. 
Harris. 
Forests of the Philippines.—A rather complete discussion of the economic 
aspect of the forests of the Philippines, based upon the investigations of 
Wuirrorp, has been issued as a bulletin of the Bureau of Forestry of these 
Islands.3 The first part deals with the classification of the various forest 
types, the importance of the diptocarp types being emphasized, the amount and 
quality of the lumber, the uses to which it is adapted, the character of the 
lumbering operations, and the forest products other than lumber. It includes 
the results of mechanical tests of 34 Philippine woods and a bibliography of 
both Spanish and English publications on the forestry of the islands. The 
second part is devoted to the description and illustration of over 100 of the 
principal tree species. The descriptions relate principally to the trunk, 
branch, leaf, and wood characters, and not to those of the reproductive parts. 
13 WuitrorD, H. N., The forests of the Philippines. P.I. Department of the 
Interior, Bureau of haveesry: Bull. no. ro. Part I, Forest types and products. PP- 
94. pls. 27. Part II, The pannel seus trees. pp. 113. pls. 103. Manila: Bureau 
of Printing. 1911. 
