3J2 DIVISION III. — MODE OF LIFE OF THE FUNGI. 



Here their further growth in length ceases; but now begins, sometimes even within 

 the soft inner layers of the skin itself, the successive ahjunction apparently in small 

 quantities of longish cylindrical gonidia, known from their shape as cylinder-gonidia, 

 partly on the extremities of the primary branches, partly on short lateral branchlets 

 (Fig 165 B). From the place of their formation these pass at once into the blood 

 which fills the cavii\- of the body, where they elongate to twice or several times their 

 original size, and divide repeatedly by transverse walls, and then begin to develope like 

 Sprouting fungi, i. e. they produce repeated orders of similiar cells by terminal and 

 lateral sprouting (Fig. 165 C). These cells are disseminated through the blood 

 by the movements of the insect and fill it by degrees in a dense mass. They 

 also penetrate into the blood-cells or are embraced by them in the course of the 

 amoeboid movement of the latter (Fig. 165 C, d). They grow at the expense 

 of the blood, which diminishes in quantity to such a degree that the insect at length 

 loses its normal turgidity, becomes soft and relaxed and in this state dies. As soon as 

 death has taken place all the sprout-cells begin to develope rapidly at the expense of 

 the substance of the dead body into copiously branching hyphae, which not only fill 

 the entire cavity of the body which till now contained the blood with a dense weft 

 and expand it to its former size in the turgescent state, but grow in a dense mass 

 through all parts of the body, except the intestinal canal which remains empty, and 

 to a great extent absorbs them. A body is thus formed in 1-2 days' time which 

 retains the shape of the living insect, but consists of a close weft of fungal hyphae with 

 some small remains of the body of the insect. This Fungus-body with the form of 

 an animal has the biological peculiarities of a sclerotium. It can give rise directly to 

 fresh stromata, and can do this in a few weeks after its formation if it lies in a moist 

 state; if it is dried, it passes into a resting-state the maximum duration of which is 

 not exactly determined, but it may certainly continue for some months without pre- 

 judice to the power of further development. Such is the course of development of 

 Cordyceps in its simplest form. 



But deviations from this course and complications of it occur not unfrcquently, 

 of which the following are the most important. If its ascospores are sown in water 

 or in nutrient solutions without a living host, they germinate and the germ-tubes 

 develope hyphae which branch with more or less copiousness according to the amount 

 of nourishment supplied ; in water only small plants are produced with few or no 

 branches (Fig. 165 A, a, L). Some of the branches spread as a mycelium in the 

 nutrient solution, and have the power, like the hyphae on the inner surface of the cater- 

 pillar's skin, of abjointing cylinder-gonidia. It is true that this has not been observed in 

 tli'- species in question, but it may be safely assumed since it has been observed in 

 Botrytis Bassiana, which agrees with Cordyceps in all these biological relationships. 

 Other branches of the germ-plants rise erect from the fluid into the air and branch, 

 forming whorls of ramifications on the extremities of which they serially and successively 

 abjoint gonidia (see p. 66). The first gonidia on the young germ-plants are cylindru al 

 like those in the body of the insect (Fig. 165 A, b), only usually shorter. All the 

 succeeding ones, even the second in a row which began with a cylindrical gonidium, 

 are spherical in form ; they may therefore be called round or aerial gonidia. The 

 mycelium also which is developed in the dead body of the caterpillar very often 

 produces gonidia of this kind only and no cylindrical ones. 



