70 BULLETIN 957, U. S. DEPARTMENT OF AGEICULTITEE. 
(2) Seventy-eight black currant bushes, badly rusted in 1914 were wintered in 
the nursery rows, and transplanted April 12, in various gardens, isolated as far as 
possible from infected white pines and currants. These were inspected six times 
during the summer, the last inspection being made on October 2. At this date all 
were still free from rust except two bushes, on each of which a few rusted leaves 
were found. There is reason, however, to suspect that these infections might have 
been due to spores carried from currants about a mile distant from the garden in 
which they occurred. In no case was rust found on any of these currants which 
were located more than a mile from a source of infection. 
(3) A number of bushes from the same source as No. 2 were planted in five lots in 
a region known from personal observation to have been entirely free from the rust in 
1914, and which is 60 miles from the nearest known source of infection. Of the 100 
bushes set out here only one developed rust, and this late in the season. All con- 
ceivable sources for this infection have been accounted for except two, viz, the 
wintering over of the rust on the currant itself, or accidental infection from spores 
carried on the writer's clothing while making an inspection on May 24. 
In 1917, V. B. Stewart (152) tested the possible overwintering of 
the fungus by means of spores adhering to diseased bushes of Ribes 
nigrum. These were heavily infected in 1915 and 1916. In August, 
1916, they were defoliated, and 200 were dug and placed in a storage 
cellar in October, where they remained all winter. In 1917, they 
were sent to Ithaca, N. Y., and set out in a field. The disease had 
not been known within 40 miles. The disease did not appear upon 
them up to October 9, 1917. 
The possibility of overwintering in Ribes buds was brought to the 
writer's attention by infections of petioles (131, 134, 135), by which 
means it seemed entirely possible for the mycelium to travel from a 
leaf blade down the petiole and thence into the stem and bud in the 
axil of the leaf. While many diseased petioles have been examined, 
no indication of the migration of the hyphas into the stem or bud has 
yet been seen. Direct examination of buds on heavily infected 
bushes has also failed to yield any indication of bud-scale infection 
(151). McCubbin (85) suggested but could not prove that infection 
of partially opened buds late in the fall might result in some of the 
infected leaflets surviving the winter and developing the disease the 
next spring. York 51 successfully inoculated the inner bud scales of 
opening buds of Ribes nigrum with seciospores, suggesting overwinter- 
ing in this way. 
The possibility of green leaves living over winter on Ribes plants 
out of dc ^rs has been investigated. In three cases, the writer had 
Ribes plants growing in pots plunged in sand out of doors at Wash- 
ington, D. C, retain green leaves through the winter until the spring 
weather of March, 1918, set in. One plant of Cumberland goose- 
berry and two plants of Utah Yellow currants did this. They were 
taken as specimens on March 22, when warmer weather set in. The 
si York, H. H. Op. cit. 
