ASCOMYCETES—EUASCI— ERGOT 275 



Claviceps, Tul. Ergot. 



Stroma erect, consisting of a sterile stem; subglobose, fertile head from 

 a subcylindrical, black, hard sclerotium ; perithecium immersed in the stroma, 

 flask shaped; asci, clavate-cylindrical ; ascospores, filiform, colorless. 



Claviceps purpurea, (Fr.) Tul. 



Sclerotium variable in length from ^ to 1 inch long or more; long 

 cylindrical; generally somewhat curved, wrinkled, purplish on the outside, 

 white within; 'usually several fruiting bodies from the same sclerotium; heads 

 spherical, tuberculose, borne on short flexuose stems; asci narrow, linear, 8- 

 spored, ascospores filiform, continuous, attenuated toward the end, 50-76 ij- 

 long. 



Ergot is a stage of a minute parasitic fungus ; although its true nature 

 was not known by early writers, it is mentioned by many of them. Lonicer, 

 about the middle of the sixteenth century, mentions its specific use. Thalius 

 applied the name of "ad sistendum sanguineum." 



Bauhin used the name of Secale luxurians. De CandoUe called it Sclero- 

 tium clavus. Although other names have been applied to it, the credit of 

 working out the life history belongs to Tulasne, one of the most eminent of 

 French mycologists. 



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 parasitic fungus, known as Claviceps purpurea. 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 color. A cross section 

 shows that the central portion is made up of closely woven hyphae or fungus 

 threads, while the edge contains 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 germinate 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 history 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 im- 

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

 distinct fungus. In this stage the mass which has replaced the ovary is soft, 

 but as it becomes older it hardens ; ultimately a hard and compact mass, the 

 ergot, is formed. 



