1 6 Minnesota Plant Diseases. 



um finally gains entrance to the interior of the insect body. By 

 continued growth of the fungus the caterpillar is killed. Its 

 substance is absorbed and appropriated by the parasite, which 

 finally replaces all insect parts with densely woven threads 

 packed with nourishment. There is thus produced a complete 

 cast of all parts of the caterpillar, life size, composed of the 

 threads of the fungus. After a rest period, this mummy or 

 storage organ produces a stalked reproductive body. In New 

 Zealand certain very large caterpillars are thus attacked and 

 the resulting storage organs are used as a food by the natives. 

 They are known as vegetable worms. 



Fungus Shoestrings or Strands. One often finds in decaying 

 logs or in soil where an abundance of woody material is present, 

 cord-like strands, often whitish in color, or in other cases very 

 dark. By tracing them along one finds them connected with 

 puff-ball fruiting bodies, or carrion fungi or gill fungi. Those 

 strands formed by the puff-ball or carrion fungus are whitish 

 in color and branch considerably ; some of the branches are very 

 small and occasionally meet each other, fusing together to form 

 a network. These threads are not absorptive in their function, 

 although the smaller branches connect directly with the ab- 

 sorptive mycelium. They serve probably in part to store up a 

 certain amount of nourishment, but their chief purpose is to 

 distribute as widely as possible the fruiting bodies and to enlarge 

 the territory from which the fungus draws its nutrition. In re-' 

 spect to the enlargement of the spore distribution such strands 

 function as do the runner stems of higher plants. 



Perhaps the most common of these strands and those to 

 which the name shoestring more properly applies, are the gill- 

 fungus strands, particularly those of the honey mushroom, 

 which is abundant everywhere in the fall. These strands are 

 found both in the ground and under the bark of trees. They 

 are dark-colored exteriorly and branch profusely and, like those 

 of the puff-balls, may form elaborate networks. The older 

 strands look somewhat like shoestrings. They may attack 

 roots of trees, penetrate the bark and spread under the latter 

 to form an absorptive mycelium which is parasitic, and which 

 may finally kill the tree. Under the bark of such dead trees 

 one finds large networks of shoestring strands and at the base 



