4 Mr. Bauer’s microscopical observations on the 
within the cavities of the germens, these young worms be- 
come of mature age, and lay their eggs within the cavities 
of these germens, which at that period nearly approach to- 
wards maturity ; and these newly laid eggs, I consider to 
be the beginning of the third generation of the worms with 
which I had inoculated the grains planted in the ground in 
October, 1807. 
Since the 5th of June, I regularly examined every second 
or third day an ear, to observe the progressive advancement, 
as well of the worms as of the germens ; towards the end of 
June, the germens assumed various distorted forms, and began 
to be filled with eggs. I extracted carefully the whole con- 
tents of one of the largest grains, and putting it into water in a 
watch-glass, I found, on examination under the microscope, 
seven large worms, a great many eggs, and at least a hun- 
dred young worms, all alive, bending and twisting in the water 
like so many small serpents. 
The natural size of the largest of these seven worms I 
found, by means of the micrometer, to be something more 
than £ part of an inch in length, and about ~ part of an inch 
in diameter. They are more of a yellowish-white colour 
than the young worms, and are not so transparent ; their heads 
are very distinct; they have a kind of proboscis, which has 
three or four joints, which they contract or extend like an 
opera glass. From the head, which is somewhat roundish, 
they taper gradually off towards the tail, which is scarcely 
half the diameter of the middle of their body, and ends in an 
obtuse claw-like point. At a short distance from the end of 
the tail is an orifice, surrounded by an elevated fleshy edge ; 
from this orifice the worms discharge their eggs. The back 
