148 EXPERIMENT STATION RECORD. 



The effects of conditions of growth upon susceptibility to fungus diseases, 

 B. M. DuGGAK (Tnuia. Mufsa. Ilort. 8oa., 1909, pt. I, pp. .j1-UG).—Iu this lecture 

 before the Massachusetts Horticultural Society the author discussed the water 

 relation, role of light, aciditj and alkalinity of soil, nutrition, and temperature 

 as factors of environment that contribute to predisposition to disease on the 

 I)art of ])l;ints. 



A contribution to the cytology of Synchytrium, S. Kusano (Bui. Col. Agr. 

 Tokyo Imp. Univ., 8 {1909), No. 2, pp. 79-1J/7, j)]s. ^). — A study has been made 

 of S. pucrari(E and 8. decipiens, in which it was found that the fungus always 

 infects the host by responding to the chemical stimulus exerted by subepidermal 

 cells which contain little or no chlorophyll. The swarm spores develop in 

 these cells, at first in a single cell, but subsecpiently causing considerable en- 

 largement by dissolving the walls of the surrounding cells and producing wide 

 intercellular chambers. 



The principal portion of the paper is taken up with a discussion of the 

 cytology of the species. 



Some differential characters of the vegetative state of Merulius lacrymans, 

 J. Beauvebie {Compt. Rend. Soc. Biol. [Paris], 66 (1909), No. 18, pp. 8Jfi- 

 S.'i2). — On account of the difficulty of recognizing the dry-rot fungus in its vege- 

 tative stage, the author has made a study of it in order to ascertain whether 

 its presence could not be diagnosed without the fruiting bodies. He has found 

 that the nuclei of the mycelium offer an excellent means for its determination. 



Recent studies on the specialization of grass rusts, ,T. Eriksson (Ark. Hot., 

 8 {1909), No. 1-3, Art. 3, pp. 26, pi. J).— A study has been made of the special- 

 ization of the crown rusts {Puccinia coronifera and P. coronata) occurring on 

 various grasses. Inoculation experiments show that there are specialized 

 forms of each species that readily infect certain grasses and not others. 

 Eight form species of P. coronifera and 3 of P. coronata are recognized and 

 their morphological and biological characters are described. 



Studies on stem rot of cereals, F. KrItger {Arb. K. Biol. Anst. Land a. Forstw., 

 6 {1908), No. 3, pp. 321-351, pi. 1). — A series of experiments has been con- 

 ducted to determine the cause of a stem rot of cereals which attacks the plants 

 near their bases. A number of fungi have been associated with this disease, 

 and the author conducted inoculation experiments with species of Leptos- 

 phseria, Dictyosporium, Ophiobolus, Hendersonia, Coniosporium, Fusarium, etc., 

 in order to find out whether they are the immediate cause of the disease, as has 

 been claimed, and also to establish if possible a relationship between some of 

 the foi'ms. 



It was found that Leptosplueria hcrpotrichoidcs occurred not only on rye 

 but occasionally also on wheat and that Ophiobolus herpotriclius attacked 

 wheat and barley and also occurred on rye. No connection could be established 

 between these fungi nor with Hendersonia hcrpotricha. It is claimed that 

 while Leptosphferia and Ophiobolus do cause a disease of cereals, they are not 

 the immediate cause of the trouble. Anything that weakens the plants, such 

 as too much rain, frost injury, etc., makes them especially subject to attacks 

 of these fungi, which are believed to be true parasites. 



The proper reference of the smut of Bromus secalinus, P. Magnus {Hed- 

 wigia, 1,9 {1909), No. 2-3, p. 100).— The author calls attention to the fact that 

 the Tilletia described as T. belgradeiisis (E. S. R., 20, p. 846) and also as T. 

 velenovskyi had been previously described by Harlot as T. guyotiana occurring 

 on B. erectus. This fungus is said to be rather commonly distributed through- 

 out Prance, Servia, Bulgaria, and probably other parts of Europe and Asia. 



Concerning the reputed relation of Myxomonas to root diseases of beets, 

 F. O. VON Fabeb {Arb. K. Biol. Anst. Land u. Forstw., 6 {1908), No. 3, pp. 352- 



