194 GRASSES OF IOWA 



its specific use. Thalius* (1588) applied the name of "ad 

 sistendum sanguineum. " 



Bauhinf used the Dame of Secale luxurians. De CandolleJ 

 applied to it the name of Sclerotium clavus. Although other 

 names have been applied to it, the credit of working out the 

 life history belongs to Tulasne, ore of the most eminent of 

 French mycologists. 



Characters of the fungus and development. — There are still many 

 persons who believe that ergot is a degenerate kernel of rye 

 or wheat, but the researches of Tulasne and other mycologists 

 have laid at rest many of the vague theories concerning it. 

 The black, purple, or dark gray spurs found in the flowers of 

 rye, wheat, and other grasses are simply one stage of a para- 

 sitic fungus, known as Claviceps j^ui'purea, Tul. These spurs 

 consist of a compact mass of threads known as the sclerotium 

 stage; it was formerly called Sclerotium clavus. 



No changes occur in ergot while it remains in the head, but 

 the following spring, when laid on damp earth, it produces at 

 different points small, roundish patches which are somewhat 

 elevated. Soon a small white head appears which elongates, 

 becoming stalked, and bearing a globular head at the tip. 

 These heads change from a grayish yellow to a pinkish colcr. 

 A cross section shows that the central portion is made up of 

 closely woven hyphae or fungus threads, while the edge con- 

 tains a number of flask-shaped bodies, the perithecia, in which 

 are found elongated bodies known as asci; each ascus contains 

 eight filiform spores, the ascospores. The ascospores ger- 

 minate and when coming in contact with a very young ovary 

 the mycelium penetrates the delicate walls of the ovary and 

 gradually displaces it. It is quite easy to trace out its life his- 

 tory by placing the ergot in damp sand and allowing it to 

 remain over winter. 



The first indication of ergot in the summer is the formation 

 of the so-called honey-dew, a sweetish and rather disagreeable 

 fluid, which is eagerly sought by flies and other insects which 

 feed upon it. This fluid contains a large number of small spores, 

 so that insects can readily carry the fungus from a diseased 

 ovary to one not diseased. These spores germinate immediately. 

 This stage is called the sphacelia, and formerly was held to be 



*Sllva Hercynla. 1588. 47. Francfourt. 

 tPinax. Theatrl Botanlca. 23. 1623. 

 $Mem. duMus. 2: 401. pi. 14. f. 8. 



