FORAGE POISONING ERGOTISM 



21 



become of great economic importance. In various parts of Iowa, for instance, 

 individual stock-owners have lost several thousand dollars from its ravages. 

 In the different localities the disease has been known by various names, such 

 as "grass staggers," "choking distemper," and "putrid sore throat," and because 

 it apparently presents some of the distinguishing characters of a specific infec- 

 tious disease, has been frequently recognized as "infectious cerebro-spinal 

 meningitis." 



A noteworthy fact however is, that thus far no evidence has been discovered 

 which would indicate that the disease is transmissable from animal to animal, 

 or that it is even inoculable. 



On the other hand, an outstanding feature in every outbreak is, that the 

 affected animals have had access to unwholesome food, either while at pasture 

 or in the stable. 



Fig. 3. Common Aspergillus on mouldy corn. 1. General appearance, showing long 

 conidiophore and sterigmata: on end. 2. Perithecium with one of its asci and ascospores. 

 3. Contents from an unripe perithecium. 4. A small part of the mycelium with conidio- 

 phore c and spore bearing sterigmata; young ascogonium as. 2, 3, 4 after DeBary. 



Geographical distribution. The disease has been reported from nearly every 

 part of the United States. It never becomes epizootic, but is usually confined to 

 isolated localities. 



While forage poisoning is not necessarily peculiar to low, poorly drained 

 districts, it is at least most frequently observed in those places where conditions 

 are most favorable for the development of cryptogamic growth. 



Etiology. The disease seems especially likely to appear when horses 

 or mules are fed on grain or fodder which has become overgrown with 



