until it fills the interior of the larva and kills
it.

In fructification a stalk rises from the body of the insect or larva and
in the enlarged extremity of this the perithecia are grouped. The stroma
is vertical and fleshy, head distinct, hyaline or colored; sporidia
repeatedly divided and sub-moniliform.

_Cordyceps Herculea._ (_Schw._) _Sacc._

[Illustration: Figure 491.--Cordyceps herculea. Showing the grub upon
which this species grows.]

Herculea is so called from its large size. The halftone will readily
identify this species. The plant is quite large, clavate in form, the
head oblong, round, slightly tapering upward with a decided protuberance
at the apex, as will be seen in Figure 491. The head is a light yellow
in all specimens I found, not alutaceous as Schw. states, nor is the
head obtuse. I found several specimens on a sidehill in Haynes's Hollow
in August and September, all growing from bodies of the large white
grubs which are found about rotten wood. They were found during wet
weather. They were identified by both Dr. Peck and Dr. Herbst.

_Cordyceps militaris. Fr._

[Illustration: Figure 492.--Cordyceps militaris.]

This is much smaller and more common than C. Herculea.
Conidia--Subcaespitose, white; stem distinct, simple, becoming smooth;
clubs incrassated, mealy; Conidia globose. Ascophore--Fleshy,
orange-red; head clavate, tuberculose; stem equal; sporidia long,
breaking up into joints. This is frequently called Torrubia militaris.

It is known as the caterpillar fungus. Its spores are cylindrical and
are produced upon orange-red fruiting bodies in the fall. As soon as the
spore falls on the caterpillar it sends out germ-threads which penetrate
the caterpillar. Here the threads form long narrow spores which break
off and form other spores until the body-cavity is entirely filled. The
caterpillar soon becomes sluggish and dies. The fungus continues to grow
until it has completely appropriated all of the insect's soft parts,
externally a perfect caterpillar but internally completely filled with
mycelial threads. Under favorable conditions this mycelial caterpillar,
which has become a storage organ, will send up an orange-red club-shaped
body, as will be seen in Figure 492, and will produce the kind of spores
described above. Under some conditions this mycelial caterpillar may be
made to produce a dense growth of threads from its entire surface,
looking like a small white ball, and from t