146 A Monograph of the Erysiphaceae 



duced on European honeysuckles a variety, lonicerae, charac- 

 terized by a slightly different branching of the apex, but which 

 occasionally shows signs of reverting to the type. 



It is, perhaps, of interest to note that in an immature condi- 

 tion, the apex of the appendages of M. alni, is often exactly sim- 

 ilar to the mature apex of the var. lonicerae. 



Allescher (3) has recorded " Microsphacra Ehrejibergii" on 

 Syriuga vulgaris from Bavaria, and has stated that the Syringa 

 affected stood in the immediate neighborhood of a bush of Loniccra 

 tatarica attacked by the same fungus. Magnus (227, p. 68) has 

 confirmed the identification, and considers the case to afford con- 

 clusive proof that the variety lonicerae (= M. Ehrenbergii) has 

 here passed over from the Loniccra to the Svrinm. The figure 

 which Magnus gives (loc. cit., /. 16) certainly seems to represent 

 the apical branching of the var. lonicerae rather than that of B'L 

 alni proper, a species which occurs very commonly on Syringa in 

 North America. 



The present variety lonicerae has hitherto been supposed to be 



the only Microsphacra which occurs on Loniccra in Europe ; the 



occurrence of M. alni, var. divaricata on Loniccra caerulea in Italy 

 is noted later. 



Var. divaricata (Wallr.). [Figs. 23-26] 



Alphitonwrpha divaricata Wallr. Berl. Ges. Nat. Freund. Verh. 

 1 : 39- 1819 ; Wallr. Fl. Crypt. Germ. 2 : 754. 1833. 



Erysibc divaricata, x^x.frangidae Lk.; WiUd. Sp. PI. 6 : 113. 

 1824. 



E. divaricata (Wallr.) Schlecht. Fl. Berol. 2 : 169 (partim). 

 1824 ; Rabenh. Deutschl. Krypt. Fl. i : 236 (excl. syn. Erysiphe 



Daphnes V^xxhy). 1844. 



3 : 244. 1829. 



frangidae Fr. Syst. Myc. 



1830. 



/' 



Gall. 2 : 870. 



E. divaricata (Lk.) Secret IMycogr, Suisse, 3 : 653. 1833. 

 Microsphacra divaricata Lev. Ann. sci. nat. IIL 15:155. 



/. 18 (sub. Calocla 



Fung. I : II. 



1882; Wint. Rabenh. Krypt. Fl. Deutschl. 1^38. 1884; 



