MlCROSPHAERA 139 



In certain specimens of J/, abii on Vicia Auicricana (usually 

 named " yJ/. Ravenelii" in herbaria) just the same occasional color- 

 ing of the appendages is found. In otherwise typical specimens of 

 AT. alni on various hosts I have frequently met with an occasional 

 colored appendage, e. g., in certain specimens on Platanus occidcn- 

 talis the coloring is limited by a septum-like line exactly as in 



"J/. 



examples on Betiila alba, where the coloring may extend to three- 

 quarters the length of the appendage. 



M. erineopJiila Peck * is another with colored appendages which 

 cannot, it appears, be considered distinct from M. alni; Peck, in the 

 original description, says " closely related to M. peiiicillata [J/. 

 alni^^, of which perhaps it may be a mere variety, but it is readily 

 distinguished by its colored appendages and nucleated spores." 

 The "nucleate" appearance of the spores may be safely disre- 

 garded as a character, and we have then only the colored appendages 

 as a supposed distinctive character separating the plant from J/ aim. 

 Relying on this point, subsequent American authors have kept up 

 M. crincopJiila as a distinct species. I cannot follow this arrange- 

 ment. In the first place, as mentioned above, we find quite com- 

 monly in ordinary M. alni the base of the appendages becoming 

 colored, and in the form described as '' M. seinitosta'" the color 

 usually reaches to half the length of the appendage. In a form of 

 M. alni on Carya alba (Rab.-Wint.-Pazsch. Fung. Eur. 3953) the 

 perithecia are exactly similar in size, and in the number and length 

 of the appendages, to those of " M. erincophila;' but as regards the 



i* 



coloring of the appendages are intermediate. The appendages of 

 some perithecia are quite colorless, of others tinged amber brown 

 throughout. If w^e were to separate the form "J/, erincophila 

 from J/, alni, the plant on Caiya alba would certainly have to be 

 included under the former— the appendages consequently would 

 have to be considered as varying from colorless to colored, and in 

 the former case the plant would only be characterized by the small 

 size, short appendages, etc.— characters which, as we have seen in 

 the case of M. Hcdzvigii, are quite insufficient. 



With regard to M. erineophila on Fagus fcrrnginea there 

 seems some connection between the coloring of the appendages 



* On " erineum "—sails on the leaves of Fagtis ferrujrinea. 



