220 ASCOMYCETES. 



" setting " of the fruit, is recommended. No fungicide should, 

 however, be applied towards the ripening season.^ 



Gibellina. 



The spherical perithecia are embedded in the stroma, their 

 necks projecting. The asci contain eight brownish spores, 

 oblong or spindle-shaped, and bicellular. 



Gibellina cerealis Pass. This parasite of wheat has hitherto 

 been fairly common in Italy ; recently it has appeared with 

 disastrous effect in Hungary. According to Cavara, it produces 

 on the under part of the stems, grey plate-like coatings with a 

 brown margin ; these may remain as spots, or enlarge till they 

 form a ring round the stem. The perithecia are little black 

 points arranged in rows, and embedded under the epidermis, 

 except the black projecting necks. The asci have thin walls and 

 break up inside the perithecia ; they contain eight spores arranged 

 in two rows. The spores are spindle-shaped and bicellular, but 

 their germination has not as yet been observed. The mycelium 

 is foimd in all the host-tissues, besides forming a stroma-like 

 sheath round the stem. The plants attacked become brown and 

 limp in early summer, and no fruit is produced.^ 



Cavara recommends early removal and burning of affected 

 stems, and the cultivation of crops other than cereals on the 

 infected ground. 



Leptosphaeria. 



Perithecia black, rarely with bristles ; at first they are em- 

 bedded in the host, without a stroma. The spores occur four to 

 eight in each ascus ; they are spindle-shaped and generally 

 multicellular by means of cross-walls only. Thread-like para- 

 physes are always present. , 



Leptosphaeria herpotrichoides de Not. This species, gene- 

 rally regarded as a saprophyte, was found by Frank ^ as a 

 parasite on rye. The stalks attacked break over at a node or 



'Further details of treatinent-experiments are given in Gall and Scribner's 

 " Report on Experiments for 1889," U.S. Amer. Dept. of Agriadture Bulletin II. ; 

 also in the Bulletins of various Experimental Stations. The above account has 

 been considerably extended by aicl from the American literature. (Edit.) 



-Cavara {Zeitschri/t f. Pflanzenkrankheiten, III., 1893, p. 16) gives a. detailed 

 account of this fungus with illustrations. 



■'Frank, Zeitschri/t f. Pflanzenhrankheiten, 1895. 



