New YorK AGRICULTURAL EXPERIMENT STATION. 225 
gray or, occasionally, purple. Frequently, the margins of affected 
leaflets were curled downward. The dichotomously branched 
condiophores occurred on both surfaces of the leaflet, but most 
abundantly on the lower surface. Violet, elliptical or ovate conidia 
were abundant. Round, brown odspores, formed within the tissues 
of the affected leaves, were common in specimens collected in Octo- 
ber and some, also, were found in specimens collected June 5 to Io. 
The dimensions of the conidia and odspores, as determined by the 
writers, are somewhat greater than are usually given for this species. 
The most common size of the conidia was 21 x 28, and of the 
oospores 35 » 1n diameter. 
On some of the leaves collected in October, there was associate:l 
with the Peronospora a Hyphomycetous fungus which may have 
been the Ovularia medicaginis described and illustrated by Briosi 
and Cavara in their Funghi Parassiti, No. 303. 
ASCOCHYTA LEAF SPOT. 
(Ascochyta sp.) 
This is an undescribed disease discovered in alfalfa fields in the 
vicinity of Geneva. It attacks the lower leaves almost exclusively. 
While it may occur on normal green leaves it is most common on 
those which have begun to turn yellow and are about ready to fall. 
In the great majority of cases it appears in the form of V-shaped, 
dead, brown areas, 5 to 12 mm. long, at the tips of the leaflets. Fre- 
quently, the spots are on the margin and semi-circular in shape, 
while in some cases circular, dead, brown spots occur on the interior 
of the leaflet entirely surrounded by healthy tissue. The boundaries 
of the spots are rather indefinite. (See Plate XXVI.) 
Between May 28 and June 12, the period during which most of 
the observations were made, pycnidia well filled with spores were 
to be found on nearly all of the spots. The pycnidia, as seen 
under a hand lens, are light brown, depressed and visible on both 
surfaces of the leaf. They are delicate in structure, 100-150 4 in 
diameter, and ostiolate with a ring of darker brown surrounding the 
ostiolum. When the pycnidia are placed in water the spores escape 
in gelatinous rope-like or wedge-shaped masses. The spores are 
hyaline, mostly non-septate, 2.5-3.5 x 6-12 , straight or slightly 
curved and rounded at the ends. Mingled with the non-septate 
spores, particularly in the more mature pycnidia, are one-septate 
spores which are often narrowed at the middle or slightly constricted 
8 
