7 H 
Journal of Agricultural Research 
Vol. XXIII, No. 9 
(9) A complete technical description of the fungus is given. 
(10) It is proved that the pathogene was brought to America from 
India with the seed. 
(11) Numerous inoculations, reisolations, and reinoculations were made 
with the use of single conidium and single ascospore strains of the fungus. 
Most of the inoculations were made by the application of conidia, with 
the use of special waxed paper moist chambers. In addition infection 
was secured by the application of ascospores alone. 
(12) Histological studies showed that penetration of the cuticle, appar¬ 
ently by mechanical means, was necessary before any injury to the host 
occurred. After penetration disorganization of the host tissue was rapid 
and complete. The fungus was found within the caruncle and even 
beneath the seed coat of seed that had been attacked before maturity. 
(13) The fungus appears to be practically limited to the castor bean 
as a host plant. Of a large list of other plants exposed to infection, only 
three other plants of the family Euphorbiaceae and a species of Pelargo¬ 
nium were slightly infected, and infection did not develop further under 
the conditions that favored rapid spread on Ricinus. 
(14) Some difference in varietal susceptibility was noted, the coarse 
ornamentals in general being more resistant than the commercial seed- 
producing sorts. Nothing promising in the way of control by this 
means was evident. 
(15) Extensive experiments indicated that control by the application 
of fungicides was entirely impracticable once the disease was well 
established. 
(16) Castor bean seed are not readily injured by any reasonable 
chemical treatment. A combination of a floating process, to remove all 
light-weight seed, with a formaldehyde treatment, would seem to be a 
practicable means of preventing the introduction of the disease from one 
locality to another by means of the seed. 
(17) Control of this disease in the event of any future heavy planting 
should consist primarily of prevention. The use of clean seed combined 
with a judicious choice of districts to be planted, based primarily upon 
freedon from recent occurrence of the disease, should result in the 
production of a mold-free crop. 
LITERATURE CITED 
(1) Blackman, V. H., and Welsford, E. J. 
1916. studies in the physiology op parasitism, h. infection by bo- 
trytis cinerEa. In Ann. Bot., v. 30, no. 119, p. 389-398, 2 fig., 
pi. 10. Literature cited, p. 397. 
(2) BriERLEy, William B. 
1918. the microconidia op botrytis cinerea. In Roy. Gard. Kew, Bull. 
Misc. Inform., 1918, no. 4, p. 129-146,1 pi. 
(3) Brown, William. 
1916. studies in the physiology op parasitism, m. ON THE RELATION 
BETWEEN “INFECTION DROP” AND THE UNDERLYING HOST TISSUE. 
In Ann. Bot., v. 30, no. 119, p. 399-406. 
(4) Cardin, Patricio. 
1918. plagas DE la higuERETA EN Cuba. In Rev. Agr. Com. Trab. (Cuba), 
, „ „ y-I> no-10. P- 527 - 533 . 7 fig- 
(5) Cotton, Richard T. 
1921. POUR RHYNCHOPHORA ATTACKING CORN IN STORAGE. In Jour. Agr. 
Research, v. 20, no. 8, p. 605-614, pi. 71-74. 
(6) Dastur, Jehangir Fardunji. 
1913. ON PHYTOPHTHORA PARASITICA NOV. SPEC. A NEW DISEASE OP THE 
castor oil plant. In Mem. Dept. Agr. India Bot. Ser., v. 5, no. 4, 
p. 177-231,10 pi. (1 col.). 
