228 



DIVISION II. — COURSE OF DEVELOPMENT OF FUNGI. 



the hymenium the well-known saccharine fluid is secreted, w 





<-°o o 



OWY 



hich oozes out from between 

 the paleae in thick drops 

 rendered turbid by count- 

 less gonidia, and thus 

 betrays the presence of 

 the parasite. This juice 

 is eagerly sought by in- 

 sects, which thus carry 

 away the gonidia. Soon 

 the formation of the scle- 

 rotium begins in the basal 

 portion of the gonidia- 

 forming body in the way 

 already described. The 

 sclerotium reaches matu- 

 rity by the time that the 

 grass is ripe and passes 

 into the dormant state 

 which lasts till the next 

 spring. The gonidia 

 readily put out germ- 

 tubes as soon as they 

 become free, and the tubes 

 sometimes produce small 

 upright branches on the 

 microscope - slide, from 

 which fresh gonidia are 

 then abscised (Fig. Ill b)- 

 Kiihn informs us that new 

 gonidiophores and scle- 



FlC. no. Clainceps purpurea, Tul. Portion of a thin longitudinal section on the boundary 

 line between the gonidiophore ss — re and the young sclerotium ?n. See Fig. 17. After 

 Tulasne, from Lurssen's Handbuch, highly magnified. 



C^ 



rotia are developed in the 

 manner described above 

 from the germ-tubes of 

 gonidia, which have found their way to the flowers of a grass. 



Neetria ditissima may be given from R. Hartig's description ' as an example of 



a species furnished with more than one kind 

 of gonidium. The mycelium lives in the rind 

 of leafy trees, and causes the disease known 

 as ' canker.' It forms a small cushion-like 

 pseudo-parenchymatous thallus beneath the 

 surface of the rind ; the thallus eventually 

 bursts through the rind and produces first 

 gonidia and then perithecia on its outer 

 surface. A sufficient account has already 

 been given of the perithecia, which in the 

 primordial state are concealed beneath the 

 gonidia and the structures producing them, 

 but these are displaced and thrust aside by 

 the perithecia. The gonidia arc now formed 

 acrogenously outside the cushion on short 

 slender filiform sterigmata arranged side by side and parallel to one another, so as to 



FlG. in. Clavieeps purpurea, Tul. a thin tr.ii 

 section through the layer from which gonidia arr 

 abscised, £ gonidia germinating and producing by abjunction 

 a small group of secondary gonidia at x. a after Tulasne. 

 highly magnified, * after Kiihn. 



1 Inters, n. d. forstbot. Instil. Miinchen, I. See also Tulasne, Carp. Ill, and R. Gothe, Der 

 Krebs d. Apfelbaume in Thiel's Landw, Jahrb. IX ,1880). 



