196 THE ASCOMYCETES 



ing essentially half those of the latter. For several seasons the 

 writers have collected sclerotia from the inflorescences of Pas- 

 pahim laeve, P. dilatatinn, and P. ftoridamnji. The sclerotia borne 

 on the heads of each of these grasses differ in average size. Scle- 

 rotial size is found to be proportional to the normal size of the 

 ripened ovaries in each of these species of grass. The perithecia, 

 asci, and ascospores, however, are all alike and correspond with 

 measurements for C. paspali. 



The complete host range of species of Claviceps can be known 

 only by means of reciprocal inoculations. Stager (1903) alone 

 conducted such studies during a period of 10 years, but his re- 

 sults should be verified and the experiments extended. He ap- 

 plied dilute suspensions of honey dew by means of an atomizer 

 to flowering grasses grown under controlled conditions. Conidia 

 of Claviceps uoilsoni from Glyceria fliiitans failed to produce in- 

 fection upon any other species, although they were applied to 

 seventeen other kinds of grass. Similarly C. sesleriae failed to 

 produce infection except on Sesleria coenilea. Claviceps pur- 

 purea itself he found to consist of several biological races. For 

 example, the Claviceps of Anthoxanthinn odoratu?n, although 

 morphologically indistinguishable from C. purpurea of rye, pro- 

 duces abundant sclerotia if used to inoculate A. odoratiiin. If, 

 on the other hand, Claviceps of rye is used as inoculum for A. 

 odoratwn^ sclerotia are almost never found, and, if they are 

 found, are very abnormal and small. 



The Claviceps of Brachypodiinn silvaticwn is also a distinct 

 biological race of C. purpurea. Br achy podium silvaticmn comes 

 into flower too late to be infected by ascospores originating from 

 sclerotia borne on this grass during the previous summer. Such 

 ascospores readily infect Milium effiisimi, however, and abundant 

 honey-dew formation results. Meanwhile B. silvaticinn comes 

 into flower and can be readily infected with conidia produced on 

 M. effusum. Numerous sclerotia develop on B. silvaticinn but 

 are very seldom formed on M. effusimi. Apparently under nor- 

 mal conditions this variety of C. purpurea requires two hosts, B, 

 silvaticinn and M. effusum. 



Barger's (1931) account deals extensively with ergot poisoning 

 through the eating of bread, especially that made from ergotized 

 rye. Numerous epidemics originating from eating bread made 

 from such rye flour have been reported. The disease results in 



