660 General and Applied Biology 



Yeasts mav cause such diseases in man as North American blasto- 

 mycosis (Gilchrist's disease)^ moniliasis (thrush), European blastomyco- 

 sis, etc. 



Higher plants such as poison ivy, poison oak, deadly nightshade, loco- 

 weed, water hemlock, etc., are poisonous for man and other animals. 

 The pollen of certain plants (ragweeds, grasses, roses, oaks, etc.) may 

 produce allergies (Fig. 256) of various types and consequences in suscep- 

 tible human beinos. 



B. Plants Pathogenic for Plants 



Bacteria may cause such diseases in plants as wilt diseases of tomatoes, 

 potatoes, melons, cucumbers, corn, etc., soft rot of carrot, cabbage, cu- 

 cumber, celery, etc., bacterial blight of beans, fire blight of pears and 

 apples, crown galls of apple, grape, raspberry, alfalfa, etc., bacterial blight 

 of walnut, canker of citrus, and many others. 



Higher fungi may cause such diseases in plants as rusts and smuts 

 (Figs. 66 and 67) of such cereal grains as corn, wheat, barley, etc., downy 

 mildew of grapes, chestnut blight, potato blight, Dutch elm disease, apple 

 scab, bitter rot of apple, brown rot of peaches, peach-leaf curl, "damping 

 off" disease of seedling plants, ergot of rye, barley, and wheat, black knot 

 of cherry and plum, leaf spot of strawberry, black spot of roses, and many 

 others. It should be noted that the disease of elms known as phloem 

 necrosis is due to a virus and is not to be mistaken for the Dutch elm dis- 

 ease produced by a fungus. 



Certain flowering plants such as dodder and mistletoe may parasitize 

 other species of plants and produce damages which may often cause the 

 death of the host. 



C. Animals Pathogenic for Animals 



Protozoa may produce such diseases in man as syphilis, amoebic dysen- 

 tery, African sleeping sickness, various types of malarial fevers, tropical 

 ulcers, kala-azar, and many others. Protozoa may cause diseases in other 

 animals such as chicken septicemia, surra in horses and other animals, 

 nagana in cattle, and many others. 



Worms may cause such diseases in man as sheep liver fluke disease 

 [Fasciola hepatica), Chinese liver fluke disease {Clinorchis sinensis), 

 blood fluke diseases (Schistosoma japojiicum, S. mansoni, S. haemato- 

 bium), Oriental lung fluke disease (Paragonimus ivesterm,ani), tapeworm 

 diseases {Taenia solium, T. saginata) , human ascaris disease [Ascaris 



