‘ two weeks and perish a fortnight later. 
FEBRUARY 15, 1901.] Z 
who made a brief informal address. later 
they were entertained at luncheon by the 
botanists resident in Washington. The 
following new members were elected: M. 
A. Carleton, Department of Agriculture, 
Washington, D. C.; F. D. Chester, Dela- 
ware Agricultural College, Newark, Del.; 
E. B. Copeland, University of West Vir- 
ginia, Morgantown, W. Va.; T. H. Kear- 
ney, Department of Agriculture, Washing- 
ton, D. C.; J. W. Toumey, Yale Forest 
School, New Haven, Conn. Officers for 
the ensuing year were elected as follows: 
President, Erwin F. Smith; Vice-Presi- 
dents, FE. C. Newcombe and L. M. Under- 
wood; Secretary, W. F.Ganong. The fol- 
lowing papers were presented, the abstracts 
of which in most cases have been furnished 
by the authors: 
Notes upon Albinism in Sweet Corn: PROFESS- 
or Byron D. Hatstep, Rutgers College. 
Complete albinism has been found in a 
sweet corn cross between ‘ black Mexican’ 
and ‘Egyptian’ after the second year. 
The tests show that the albinos come from 
the white, pink and purple grains in about 
equal numbers and in some instances fifteen 
per cent. are white plants. These albinos 
have the normal vigor and in every way ad- 
here to the type, except in the lack of 
a capacity to produce chlorophyll. They 
begin to lag behind their green mates after 
In 
the dark they grow like the normal plants, 
except that no etiolin is produced. A large 
number of seeds, germinated under unfavor- 
able conditions, were not influenced in the 
percentage of albinos, and it seems quite 
certain that the albinism is acquired before 
the tests were made. Some ears in the lot 
of crossed corn produced no white plants, 
while others show many, and it seems to 
be a fact that grains from overburdened 
plants, ¢. g., where there are three large 
ears, are more apt to produce albinos than 
SCIENCE. 
247 
those from stalks with a single ear. The 
cross may have been such that the last act 
in the drama of perfect seed-production was 
not reached. Again, the close breeding of 
the crossed grains, all plants in the plot be- 
ing of the same mother and with no pollen 
from other plots, may have had its effect 
in the manner mentioned. 
A Disease of the Locust: Dr. HERMANN VON 
ScHrenkK, Shaw School of Botany. 
A destructive disease of the black locust 
(Robinia Pseudacacia), due to Polyporus 
rimosus, was described. The fungus de- 
stroys the heart wood of this tree, leaving a 
soft, yellow mass. The fruiting organs 
form on the trunk and larger branches for 
many years, discharging their spores in the 
summer and fall. Attention was called to 
the fact that the mycelium grows only in 
the heart wood of living trees, and dies as 
soon as a tree is cut down. This is prob- 
ably due to changed conditions of aération, 
moisture and temperature. This fungus 
must be considered as a special class of 
saprophyte. 
Observations on the Mosaic Disease’of Tobacco : 
Mr. Ausert F. Woops, Department of 
Agriculture. 
The author presented the results of 
numerous experiments showing that the 
mosaic disease of tobacco may be artificially 
produced in the following ways: (1) Bycut- 
ting plants back during any stage of active 
growth, thus removing most of the re- 
serve organic foods and stimulating rapid 
growth of lateral buds in the absence 
of sufficient albuminoid reserve. This 
causes a remarkable increase in the activ- 
ity of oxidizing enzymes. These enzymes 
inhibit the action of the translocation dias- 
tase of the cells, thus preventing the move- 
ment and assimilation of starch. When a 
plant once reaches this stage it seldom re- 
covers, all new growth becoming diseased. 
He was able to produce the same disease in 
