Entomophytes, or Entomogenous Fungt. 487 
Rhyssonotus, Cicada, Pielus, and Trictena, all of which live 
underground at the roots of plants. i 
For an account of the general structure and development of 
the entomogenous fungi we cannot do better than turn to the 
writings of Dr. Cooke. This writer * says, “ there are four 
groups under which the fungi parasitic upon insects would 
primarily arrange themselves, and these, in the order of their 
importance, would be: first, the ascigerous or Cordyceps 
group, which have mostly a fleshy stroma, a club-like shape, 
and sporidia contained in asci, including also those imperfect 
forms or conidial states which belong or are allied to Jsarva. 
... The first group consists of... entomogenous species, to 
which at first the generic name of Clavaréa was applied, until 
their structure and fructification were ascertained, but which 
were afterwards transferred to the large genus Spheria, on 
account of their possessing the cells called perithecia, in which 
the sporidia were developed, enclosed in long delicate sacs or 
asci. When a division of Spheria took place subsequently a 
new genus, termed Cordyceps, was characterized, to which 
the entomogenous species, with some few others, were 
assigned, on account of their fleshy vertical stroma and peri- 
thecia, with long filiform sporidia. 
“'The general and typical form in Cordyceps is a somewhat 
club-shaped erect body, sometimes only a few millimetres and 
sometimes several inches in height, with a naked, sterile, solid 
stem, attached by threads of mycelium, and a thicker head, 
globose, oval, or elongated, which is covered on all sides with 
nearly globose perithecia, immersed in the substance, and only 
visible externally by their dot-like mouths or orifices. Ina 
few instances the perithecia are only partially immersed or 
nearly free, but such instances are rare. At first the perithecia 
contain only a minute drop of grumous gelatin, but finally 
this is differentiated into very long cylindrical asci, with a thin 
membrane, each containing eight long thread-like sporidia, 
which are commonly nucleate, then septate, breaking up finally 
into separate joints, each of which is a reproductive unit. 
“'The vegetative portion, or mycelium, at the base pervades 
the body of the host-insect, commencing in many instances 
during life, and at length absorbing the whole interior, con- 
verting it into a fungoid mass. ‘The external stroma, consti- 
tuting the fungus proper, notwithstanding all that has been 
written to the contrary, is not developed until the whole inte- 
rior is absorbed, and consequently the insect is dead.” 
* Hist. Ent, Fungi, p. 1. 
