Minnesota Plant Diseases. 



73 



mal was completely covered. Meanwhile the puppy gradually 

 grew sluggish and finally died. Soon after death the fungus 

 had formed around the mud puppy's body a dense mass of mold 

 almost an inch thick. All the mud puppies left in the same 

 aquarium were finally killed by this mold. 



Diseases of birds. Birds are not without their fungus para- 

 sites. However, these parasites are members of a different 

 group of fungi from those inhabiting fishes and amphibians. 

 In the latter the parasites are adapted to aquatic habits while 

 on the birds one finds fungi which have become adapted to 

 aerial life. The birds offer somewhat analogous advantages 

 to fungi which one finds among insects ; that is to say, abun- 

 dant aeration furnished by the bird habit of life. One fungus 

 disease of birds is caused by forms of the green molds which 

 affect particularly the respiratory organs causing inflammation 

 of the affected parts. Almost all classes of birds have been 

 reported as hosts of these parasites. Chickens sometimes suffer 

 from a comb scab which is also of fungus origin. This fungus, 

 when raised on gelatine plates, shows similar life habits to the 

 yeast fungi. In this disease scabs are formed on the comb and 

 the fungus inhabits the scab spots. The same form, or a close 

 relative of it, may attack the crop of the chicken and form a 

 pustule disease. Hens' eggs, as has already been mentioned, 

 are not infrequently attacked by fungi of the green or black 

 mold group and egg rot ensues. Such fungi may, however, be 

 mere saprophytes living on the albumen of the egg. 



Diseases of lower mammals. There are several diseases of 

 considerable importance among the mammalians. The most 

 serious of these is the disease of cattle known as lumpy jaw. 

 The cause of this disease is apparently a fungus but its position 

 in the classification of fungi is not yet known because its spores 

 have never been observed. It occurs in little nodules which ap- 

 parently multiply very rapidly. It attacks most commonly the 

 jaws and mouth parts of cattle and the diseased animal's head 

 becomes much swollen and presents the lumpy appearance 

 which gives the disease its common name. The results are 

 usually fatal. Infection apparently takes place from the food, 

 particularly from the hay and grain foods, upon which the fun- 

 gus has been found to exist. The fungus is probably intro- 



