70 A Monograph of the Erysiphaceae 



and safe remedy is found in the use of evaporated sulphur. The 

 author gives these directions : '' In the use of this remedy a 

 small kerosene stove with a thin iron kettle was used, and the 

 sulphur kept boiUng two or three hours thrice each week, when the 

 house was kept closed. Care must be taken that only enough 

 heat is used to boil the sulphur, and that it is not set on fire.'' 

 Gucrcio and BaronI (loi*) recommend as a fungicide the follow- 

 ing mixture: carbonate or crystals of commercial soda, kg, 1,5 , 

 Norwegian vegetable tar, kg. 0.5; water, liters 100. The soda 

 and tar must be boiled together in about two liters of water, and the 

 rest of the water then added at the ordinary temperature. Spray- 

 ing with this mixture is stated to have been completely successful 

 in checking the disease in cases where the use of sulphur and sul- 

 phate of copper had little effect 



The records of *' S, pannosa'' on gooseberry in America be- 

 long to vS. mors-iLvae ; those on Rubns, and probably also on rasp- 

 berries, to S. liumuli. The record of S. pannosa on Spiraea ill- 

 inaria (391) probably refers to 5. hiumdu Worthington G. Smith 

 (330) states that .S". pannosa *' sometimes grows on Spiraea and 

 the hop, but hop-mildew is of course a different fungus/' Here 

 again, notwithstanding the concluding remark, 5. huuiuli has prob- 

 ably been confounded with the present species. 



3. S. MORS-uvAE (Schwein.) Berk, and Curt. 



Erysiphe niors-iivae Schwein. Syn. Fung. Am. Bor. 270. 

 1834. 



Sphacrotheca mors-iivae (Schwein.) Berk, and Curt. Grevillea, 

 4: 158. i8;6; Sacc. Syll. Fung, i : 5. 1S82; Burr, and 

 Earle, Bull. 111. State Lab. Nat. Hist. 2: 399. 1887; Burr.; 

 Ell. and Everh. N. Amer. Pyren., 7. 1892. 



Albigo ijiors-uvac (Schwein.) Kuntze, Revis. Gen. Plant. 3^ : 

 442. 1892, 



Exsicc. : Rab.-Wint. Fung. Eur. 3239; EII. and Everh. N. 

 Amer. Fung. 1536; Roumeg. Fung. Gall. Exsicc. 3882. 



Amphigenous ; mycelium persistent, when mature forming 

 dense pannose patches, composed of sparingly branched, more or 

 less flexuous, brown hyphae, which are about 5 // wide, at first 

 pale brown and plainly septate, becoming dark brown and thick- 



