ia 1905] CURRENT LITERATURE 477 
PAMMELSS has given an interesting account of the Iowa species of Gymno- 
sporangium whose aecidium or roestelia stage causes the rust of apple leaves. 
The species described are: Gymmnosporangium globosum, macropus, clavipes, 
midus-avis, and clavariaejorme. A considerable number of inoculation experi- 
ments are here reported, showing the genetic relationship between the teleuto- 
sporic stage on the red cedar and the roestelia stage on apple and other rosaceous 
plants. Pammet has not secured as good results in combating the apple rust 
by Bordeaux spraying as was reported by Emerson.3° The removal of the 
cedar-apples is again recommended as the best method of preventing injury from 
the apple rust.—E. Mrap Witcox. 
. SHELDON37 has published an account of his investigations in West Vir- 
_ ginia of the anthracnose of the watermelon, due to Colletotrichum lagenarium, 
_ and minor notes regarding a few of the other diseases of cucumbers and melons. 
The anthracnose was successfully combated by spraying with the usual Bor- 
deaux mixture, but the cupram did not give so good results. In a later bulletin,3® 
in a way a preliminary hand-book of the diseases of that state, he presents brief 
_ hotes regarding some of the more important diseases of cultivated plants observed 
__ in West Virginia during 1903 and 1904.—E, Mrap WILCo 
MInsseEn_holds3° that the experiments of BLANCK‘° were faulty in method 
and his data consequently incorrect, invalidating his conclusion that the diffusion 
of water in humus soils is retarded by the presence of free humus acids. MINSSEN 
finds, on the contrary, that neither free humus acids nor other organic or mineral 
acids in dilute solutions can diminish the rate of diffusion of water or of salt 
Solutions. The physiological dryness of humus soils, then, cannot be due to 
the free humus acids, nor can these influence plant growth in this particular. 
eo. R. B 
In tHE Report of the Botanist+* of the Hatch Experiment Station of Massa- 
- chusetts for 1904 there is given a bibliography of great value to the plant patholo- 
gist. It includes, as the title states, “Some important literature relating to dis- 
(ee 
35 PAMMEL, L. H., The cedar apple fungi and apple rust in Towa. Bull. Iowa 
ee. Stat. 84: 1-36. fas. I-IT. 1905. 
36 EMERSON, R. A. , Apple scab and cedar rust. Bull. Neb. Exp. Stat. 88: 1-21. 
Mit I-90. Sce Bor. Gazerre 40:149. 1905. 
37 SHELDON, J. L., Diseases of melons and cucumbers during 1903 and 1904. 
- Va. Exp. Stat. 94: 119-138. pls. I-5. 1904- 
a 38 sccm, J. L., A report on plant diseases of the state. Idem 96:69-99- 
_ Pl. 6 (not numbere d). 
_, %Murnssen, H., Ueber die Diffusion in sauren und neutralen Medien, insbesondere 
im Humusboden Lk ndw. Versuchs-Stat. 62:445-476. 1905. 
Pisce Ueber die Diffusion des Wassers im Humusboderi. Idem 58:145- 
gor. 
* Stone, G. E., Rept. 17, Mass. Hatch Exp. Stat. 1904: 31-34. 1995- 
