CHAPTER XLIV 



THE FUNGI 



<^<^<><><^o<><>c><x><^c>C'<><><^o<^^ 



Slightly moist bread in a warm room soon becomes covered with fila- 

 mentous molds. Clothing, leather, and books left in moist rooms are soon 

 "musty" because of the development of other kinds of molds. The flavors 

 of some kinds of cheese are due to the growth of blue and green molds. 

 Around old stumps in meadows, and within forests where organic mat- 

 ter is abundant, puff balls, mushrooms, and toadstools may be found 

 (Fig. 234). From decaying logs and even from standing trees bracket 

 mushrooms often protrude ( Fig. 247 ) . Field and garden crops are often 

 infected with rnildews, rusts, and smuts. In the process of bread-making 

 yeast causes the dough to "rise." Many animals, including man, suffer 

 discomfort through skin invasions of molds which cause, among other 

 diseases, "ringworm" and "athlete's foot." Some of these plants are 

 saprophvtes, some are parasites, and some live as both saprophytes and 

 parasites. All these plants collectively are called fungi (sing, fungus). 



How are fungi recognized? We have already learned that non-green 

 plants include fungi, bacteria, an occasional alga, and some seed plants. 

 The name fungus is the old Latin word for mushroom. Just as it is diffi- 

 cult to tell whether some organisms are plants or animals, the great 

 diversity among fungi makes it equallv difficult to distinguish clearly 

 certain fungi from certain bacteria and algae. The most common charac- 

 teristic of fungi is a vegetative body of either a loose web or a compact 

 mass of filaments none of which contains chlorophyll (Fig. 235). The 

 fruiting and reproductive bodies of numerous fungi are readily recog- 

 nized, but the reproductive bodies of many common fungi are seldom 

 found; hence some fungi must be recognized without them. 



Vegetative parts of a fungus. A toadstool among the leaves on the forest 

 floor, or a bracket fungus on a fallen tree trunk is but a small part of the 

 fungous plant. The part not readilv seen consists of a widely dispersed 

 mass of filaments (Fig. 235). In describing fungi these filaments are 

 called htjphae (sing, hijpha). Hyphae are either continuous tubular 

 structures, or divided by cross walls into cell-like segments containing 



541 



