Chapter II. 



Fungi. Reproduction. 



The fungus method of reproduction. Fungi reproduce by 

 means of very small bodies of microscopic size, which are 

 known as spores.* All of the spores of fungi are not similar in 

 origin, structure or appearance, but dififer in these respects 

 very considerably. Some spores are pinched off, as it were, of 

 special fungus threads, often in rows, as in the summer spores, 

 of mildews. Others, again, are formed in cases, as in the small 

 black heads of black molds; or in sacs, as in the morels and 

 cup fungi. Again, a spore may be formed as the result of a 

 breeding act — i. e., the fusion of two sexual elements which 

 may be both alike or may be male and female. Some spores 

 are provided with fine thread-like processes and by whipping 

 these about can swim around in the water. Such spores are 

 found in the potato-blight and in many water-inhabiting forms, 

 as fish-molds. Many spores are capable of germinating im- 

 mediately while others require a long rest period and are there- 

 fore provided with thick protective coats. The summer or 

 red-rust spores of grass rusts commence to grow as soon as 

 they are ripe, if the conditions are otherwise favorable, and this 

 fact accounts in part for the rapid spread of rust in certain 

 seasons. The winter spores of rust, or black rust, have thick 

 protective coats and usually rest over until the following 

 spring, when they continue their further development. 



In the bread-mold and its allies, in the fish molds and in the 

 potato-blight relatives, no complex organs are formed upon 

 which the spores, whether pinched off or in cases, may be ag- 



"The term spore might better, as is advocated by many botanists, be retained for the 

 equivalents of the spore of the moss sporogonium and all other sporophytes. This restric* 

 tion would exclude the term from the realm of fungi with the exception of perhaps the 

 sac spores of the sac fungi and certain spores of the algal fungi, and perhaps also the 

 sporidia of the rusts. Convenience and established usage would seem to counsel here the 

 retention of this teim in the older and commonly accepted sense. 



