56 
Heavy dews or rains favour the locomotion of these larvae or make it 
possible; they cannot endure sunshine and even object to bright 
daylight ; but on rainy days they move about on the ground until noon 
and even longer, then they vanish under the leafy covering of the forest 
ground. If their line of march be interrupted they as fast as possible try 
to re-unite themselves. A woman from the Thuringian Forest once saw 
the Host-Worm creeping across the road like a terrible snake so long that 
neither head nor tail was visible. She took heart and crushed it in several 
places with her foot, but to her great terror it soon grew together again. 
Seized with a sudden fear she took flight and for a long time would not 
pass that road, for she thought that a crushed snake having power to 
quickly grow together again could certainly bring misfortune on men and 
beasts. 
If we carefully examine the leafy covering of the forest ground we find 
that in spring and summer it is never uniform as the fall of the leaves in 
Autumn formed it, for winds and gales clear away the leaves completely 
in some places and heap them up higher and higher in ditches, low grounds or 
otherwise protected situations. We also know further that the amount of 
moisture in the ground and in the overlying mass of leaves varies much 
according to the geological formation of the ground, the compactness of 
the forests, the direction of the slopes of the mountains and the presence of 
wells, brooks and rivulets. These facts together with the conditions of 
the weather furnish us with an explanation for the wanderings of the Host- 
Worm; and although it was formerly considered that the larvae were in 
search of decaying animal bodies or offal, it was discovered in 
1867 that they live chiefly if not exclusively upon the layer of decaying 
leaves covering the ground of the forests ; consuming only the cellular tissue 
and sparing even the smallest and most tender veins so that a more or less 
perfect skeleton of the leaf is left. Continued fine weather makes the 
layer of leaves under which they live too dry, and an unusual quantity of 
rain soaks it too much; in the latter case they usually come to the surface 
and consume the upper softened leaves, but creep down again when these 
bocomo too dry ; thus it is evident that the mass of leaves forms the natural 
food of these little creatures, and must neither be too dry nor attacked by 
mould or mildew. Living as they do in great numbers together and 
requiring as do all insect larvae a large amount of food, it is not surprising 
that they must go in search of a new feeding ground as soon as the old one 
is cleared, resembling in this respect the Caterpillar of the procession 
spinner: and we are quite justified in drawing the conclusion that this 
quest is the sole object of the marches. 
