16 THE BOTANICAL MAGAZINE. h™. xxix. No. sss. 



In 1900, E. S. Salmon (7) published a valuable monograph 

 of this family. He decided the limitation of the family as 

 follows : — 



" The Erysiphaceae are characterized by the truly parasitic 

 habit, the white mycelium, the production of large, colorless 

 (or white) non-septate conidia on simple, erect conidiophores 

 (forming the Oidium-stage) , and the indehiscent perithecia, or 

 cleistocarps (mostly provided with appendages of a very definite 

 form), containing non-septate ascospores." 



He excluded from this family the genus Saccardia Cooke 

 which has the muriform ascospores ; and he did not recognize 

 the genera Erysiphella Peck and Pleochaeta Sacc. et Spec, 

 as distinct and valid as they were known to have been based 

 on the imperfect specimens of Erysiphe and Uncinula. He re- 

 tained the six genera already proposed by Leveille. These 

 genera were classified into two sub-families based on the opin- 

 ion of Palla. 



In 1901, F. W. Neger (4) investigated the structure of the 

 perithecial wall in many species and divided this family into 

 four biological groups according to the behavior of the ripe 

 perithecia, (1. Perithecia falling off or not when ripe, 2. Methods 

 of detachment, and 3. No or well-marked differences of the 

 structure in the upper and lower halves of the perithecium). 

 Thus he has raised De bary's section "Trichocladia" of Erysiphe 

 to generic rank, by the fact that the perithecia fall off when 

 ripe and the well-marked difference of the structure of the per- 

 ithecial wall is present in the upper and lower halves. 



In 1902, Salmon (9), however, stated that this arrangement 

 is not desirable and " impossible to draw a satisfactory line 

 between " Trichocladia " and " Microsphaera". At present, 

 Neger's Trichocladia is not generally accepted by authors. 



In 1906, Salmon (11) published the result of investigation 

 on Erysiphe taurica Lev., in which mycelium is " at first wholly 

 endophytic producing conidiophores sent up through the 

 stomata," and perithecia are " produced on the hyphae of a 

 superficial mycelium originating from the endophytic mycelium." 

 Moreover, examinating the type specimen of Oidiopsis sicula 



