44 Minnesota Plant Diseases. 



ing dries out the cloth and the fungus perishes. Moldy clothes 

 have usually lost their firmness because the fibers have been 

 partially disintegrated and weakened by the fungus. 



Egg-inhabiting fungi. Not all rotting of eggs is caused by 

 fungi, as bacteria are chiefly responsible for these processes. 

 Mold fungi, however, do occasionally penetrate, especially 

 through the cracks in the shells, and live saprophytically upon 

 the albumen. The latter makes an excellent nutrient material 

 and the fungus usually thrives here though it cannot form any 

 spores unless air is admitted. The keeping of eggs in lime or 

 in cold storage serves the same purpose — the prevention of the 

 development of fungi and bacteria. 



Half-saprophytes. Intermediate between pure saprophytes 

 and pure parasites are those fungi which can live under either 

 conditions of life. Some are, however, typically saprophytes 

 and are usually found growing under saprophytic conditions, 

 but are capable of parasitic life under other conditions. As a 

 I'ule, such fungi do not show any great specialization or exact 

 selection in their parasitism. They are not confined in their 

 parasitic life to certain specific kinds of host plants but often 

 attack plants of widely related groups. 



Ripe rots of fruits. Alany of the fruit rots are due to fungi 

 of this class. Some of the green molds and also of the bread 

 molds are able to penetrate the thin skin of some fruits and 

 attack the living cells within in the manner of a parasite. In 

 the killed portions the fungus continues to live as a saprophyte. 

 The living substance in most fruits is at the time of ripeness 

 practically dormant and contains a great deal of food material, 

 both of which conditions serve to make it easier for those fungi, 

 which have not yet learned thoroughly, but only in an amateur- 

 ish way, the parasitic life, to obtain nourishment. The low vital- 

 ity of the fruit-cell protoplasm is insufficient to ward off the at- 

 tack and the large amount of nourishment is an alluring reward. 

 Hence these molds may live for a short time as parasites and 

 then continue their saprophytic fife. In fruits a great deal of 

 sugar is stored up and this furnishes the nutrition. The fungus 

 gains entrance through thin-skinned fruits or through cracks in 

 the skins. Those with thick skins are capable of warding oflf 

 such fungi. Bruising or crushing of berries or fruits may not 



