612 Microscopical Fungi Infesting our Cereals. (October; 
Fic. 1v.—Same from above, the sculpture represented only on the first segment, 
Ter me times. 
Fic. v.—Same from the side, enlarged forty-eight times. 
Fic. v1.—Tubercles on the — surface of the segments near their junction, en- 
dii two o husideed and fifty tim 
Fic. vil.—Leg, enlarged fifty 
Fic, VIII RE 8 and ite a the back, enlarged two hundred and fifty 
times. 
:0: 
MICROSCOPICAL FUNGI INFESTING OUR CEREALS. 
BY WM. BARBECK. 
I. Ergot—In examining a rye-field about harvest time we may 
be pretty sure to find some plants in which, although the ears 
with their bracts or glumes are apparently developed in a normal 
way, some of the grains have attained an abnormal size and are 
of a somewhat blackish color. We have here what is generally 
known as “ Ergot” (botanically Claviceps purpurea Tul.), a fungus 
which is to be found almost exclusively on rye, and which, 
because of its poisonous effects on animal organisms, is dreaded, 
particularly in those parts of Northern cae where rye bread 
forms the staple daily food. 
his fungus shows three distinct stages of development, two of 
which were well known to former botanists, but were described 
as separate species belonging to entirely different genera. It is 
to Tulasne that we owe the discovery of their immediate connec- 
tion and succession. 
Towards June, when the sexual parts have been differentiated, 
we see a mucous, honey-like substance flowing from out of the 
bracts of the ear. In examining this “honey-dew” (as it is 
called by farmers) under a microscope of high power, we behold 
it swarming with millions of minute oval spores, or conidia, 
which upon further examination we find to issue from a delicate 
but complicated mycelium which penetrates the ovary, gradually 
transforming it into a soft whitish body of an oblong shape with 
shriveled surface. In this form our fungus was described and 
recorded by Leveillé as Spacelia segetum. 
In the course of a few weeks the gelatinous membranes of the 
mycelium-threads harden and assume a brownish color. Thus 
the originally soft tissue is transformed into a body of a corky or 
1 Read before the Biological Section of the Academy of Natural Sciences, Phila- 
_ delphia. ' . ‘ 
