514 
DONALD REDDICK 
The writer undertook an investigation of somewhat similar nature, 
using the bean, Phaseolus vulgaris, as host and Fiisarium martii phaseoli^ 
for the parasite, a fungus that has been shown by Burkholder^ to be 
the cause of a serious disease of beans in New York. 
The work was performed in the laboratory of plant physiology of 
the Johns Hopkins University, Baltimore, Maryland, where the writer 
was fellow by courtesy during the academic year 1 916-17. His 
thanks are due the authorities of that institution for the facilities af- 
forded him and special acknowledgment is made of the critical advice 
given him by Prof. B. E. Livingston, under whose immediate guidance 
the work was done. While the investigations are by no means com- 
pleted, some of the physiological features of the results thus far ob- 
tained are of sufficient interest to w^arrant this note. 
The plants were grown in cylindrical vessels of tinned sheet-iron, 
17 cm. tall and 15 cm. in diameter, which in turn were placed in a 
water bath. The garden soil used was first heated in an autoclave 
for one hour at a temperature of 1 10° C. and it was then made uniform 
by repeated sifting. The culture vessels were filled and nearly uni- 
form packing was obtained by letting the soil fall into place always 
from the same height. Water was supplied by means of the Livingston 
auto-irrigator,^ two cylindrical porous clay cups being used, each with 
an exposure to the surrounding soil of approximately 121 square 
centimeters. 
The irrigation water was drawn directly from the water of the bath 
and care was taken to have the supply uniform, so as to avoid difference 
in soil moisture content that might influence the growth of the plants. 
Since the water level was nearly as high outside the cylinders as was 
the level of the soil within, it was necessary, while the plants were 
'•^ Burkholder, W. H. Some root diseases of the bean. (Abstract.) Phy- 
topathology 6: 104. 19 1 6. Bean diseases in New York State in 191 6. (Ab- 
stract.) Phytopathology 7: 61. 191 7. 
Burkholder states that Fusarium martii Ap. & Wr. does not produce infection 
on the bean but that the fungus from bean is nearly identical with this species. 
The name martii phaseoli has not been used previously and is only introduced here 
as a matter of convenience. 
Livingston, B. E. A method for controlling plant moisture. Plant World 
11: 39-40. 1908. 
Hawkins, Lon A. The porous clay cup for automatic watering of plants. 
Plant World 13: 220-227. 1910. 
Livingston, B. E., and Hawkins, Lon A. The water-relation between plant and 
soil. Carnegie Inst. Wash. Publ. 204: 3-48. 191 5. 
