Davis—Parasitic Fungi of Wisconsin. 
757 
683a — var. thalictri n. var. 
On Thalictrum dioicum L. Radisson. 
Pycnidia smaller; sporules 8—10 X 2—3 microns. 
683 b. Ascochyta (?) infuscans E. & E. 
On Ranunculus abortivus L. Racine. This was 
doubtfully referred to Ascochyta by the authors 
because the sporules in the type material were 
binucleate and it was thought probable that they 
became uniseptate. The sporules of the Racine 
specimens are 2—4 nucleate and when treated 
with dilute iodine or methyl green-acetic acid so¬ 
lutions the cytoplasm is seen to be 1—'3 divided 
but there are no true septa. In germination the 
sporules swell and become torose with one to 
three constrictions and at these points constrictive 
division begins. When germinating actively how¬ 
ever germ tubes are given off, usually at one or 
both extremities, and the nuclei and cytoplasm 
pass out of the sporules before the divisions are 
completed. Some of the sporules, however, do 
not form germ tubes but divide into 2—4 cells 
which separate and some at least of these second¬ 
ary sporules, if the term is allowed, become uni¬ 
septate without constriction. The effects of this 
parasite upon the host are serious, causing speedy 
death of as much of the plant as is distal to the 
point of attack and in moist weather such dying 
portions are usually covered by a growth (Botrytis 
as I have seen it) that seems to inhibit the de¬ 
velopment of the pycnidia, so that it is only in 
comparatively dry weather that I have been able 
to get satisfactory specimens. Stems, branches 
and petioles are attacked as well as leaves. In 
June, 1908, I secured fresh mature material the 
sporules having oozed out in cirri. These sporules 
were quadrinucleate and germinated speedily in 
slide cultures producing both terminal and lateral 
germ tubes without the torose swelling. 
