PARASITIC FUNGI AND MOULDS. 43 
VI. Hanirar or Parasitic FUNGI: THEIR DrEstTRUC- 
TIVE ACTION. 
The habitat of parasitic fungi is extremely varied. 
Roumegutre, in his Cryptogamie illustrée, has devoted 
more than forty pages of a large quarto, printed in 
three columns, merely to the enumeration of fungi, 
classified according to their position in plants, animals, 
organic or inorganic substances, and the author himseli 
admits that this list is far from complete. 
Parasitic fungi are found on plants belonging to 
all the families of the vegetable kingdom, and also 
on other fungi; on living animals, vertebrate and 
invertebrate; on their dead bodies and on excrement; 
in stagnant waters and in the sea, on piles and rocks. 
Others prefer marshes, turf-bogs, heathy ground (which 
may be marshy or dry), dunes, caves and holes, and 
even completely covered by the soil, as is the case 
with truffles. Others, again, erow upon stones, walls, 
and rocks; in the open air or in ruins; or, like Zorula 
conglutinata, and Himantia cellaria, in the darkest 
caves, where they form a species of feltwork, often 
several centimetres in thickness, of a blackish colour, 
ragged, and extremely light, which in the course of 
a few. years overspreads the walls of cellars. Other 
fungi inhabit our houses, attack our food, clothes, 
utensils of every kind; wall-papers and books, of 
which the paste offers a nutriment which they can 
