A NUTRITIONAL STUDY OF INSECTS 55 



gus which grows on this comb (as in the case of ambrosia beetles, 

 really upon food cut by the insect, but largely indigestible to them, 

 is described by Fetch ('06) as follows: 



The mycelium on the comb bears small, white, stalked or almost ses- 

 sile 'spheres.' These consist of branching hyphae bearing either spher- 

 ical or oval cells. The spherical cells do not germinate. The oval cells 

 germinate readily but it has not been possible to reproduce the 'spheres' 

 from them. When the comb is old an agaric grows from it. This 

 agaric appears in two forms, one of which has lieen assigned by various 

 mycologists to Lentinus, Collyl^ia, Pluteus, Pholiota, and Flammula, 

 and the other to Armillaria. It develops in a cartilaginous, almost 

 gelatinous, universal veil and is a modified Volvaria. Other fungi which 

 grow on combs removed from the nest include Mucor, Thamidium, 

 Cephalosporium, and Peziza. As these are not found in the nest, 

 though some of them are capable of development underground, it is 

 probable that the termites 'weed out' foreign fungi from the cultiva- 

 tion of the coml). The comb material is probably sterilized by its passage 

 through the alimentary canal.^^ That the spheres form the food of the 

 termites is probable, as in the case of the leaf-cutting ants; neither case 

 can be considered definitely proved. Termes redemanni and T. ob- 

 scuriceps undoul)tedly prefer fungi, or wood which has been attacked by 

 fungi .... It is most probable that the 'spheres' in the ter- 

 mite comb and the 'Kohlraljihaufchen' of the leaf-cutting ants investi- 

 gated by MoUer are parts of a normal mycelium, and that their shape is 

 modified by the insects only in a very slight degree, if at all . 

 The availa])lc evidence appears to show that the 'spheres' are part of 

 the mycelium of the Volvaria, but it has not been possible to connect 

 these forms experimentally. 



The fungus gardens are found in all chambers except the royal 

 chamber; here the queen lies in state and is fed (Doflein) with a 

 concentrated and easily assimilated food consisting of mycehal 

 spherules by the workers. The larvae, according to Fetch, do 

 not show the presence of any spherules in the digestive tract, but 

 may be fed on some regurgitated or predigested food furnished 

 by the workers, which in turn feed on decaying wood. It is of 

 interest that the queen termite is the only known adult insect 

 which increases in size. The queen is usually the center of a 

 pool of fatty secretions on which the workers feed with great 

 satisfaction. 



21 Mv italics. 



