ASCOMYCETES 215 



Control. A thorough study of effective methods of control has 

 been made under conditions in Florida, and it has been found 

 that the most effective preparation there tested is the resin wash. 

 This mixture consists, according to Webber, of the following 

 ingredients : 



Resin 20 Ib. 



Caustic soda, 98 per cent 4 Ib. 



Fish oil, crude 3 Ib. 



Water to make "... 15 gal. 



He prepares this mixture as follows : Place the resin, caustic soda, 

 and fish oil in a large kettle. Pour over them 1 3 gallons of water, 

 and boil until the resin is thoroughly dissolved, which requires from 

 three to ten minutes after boiling has commenced. While hot add 

 enough water to make just 1 5 gallons. It is advised to make about 

 two sprayings when the insect is in the larval stage. In Florida, 

 winter sprayings are important, but a spraying in May is also often 

 desirable. In all cases dilute the stock solution with 9 parts of 

 water. 



XXI. ERYSIPHACE^ 



BURRILL, T. J., and EARLE, F. S. Parasitic Fungi of Illinois. 111. State Lab. 



Nat. Hist. 2: 387-432. 1887. 

 DE BARY, A. Beitrage zur Morphologic u. Physiologic der Pilze 1 (13-14): 



23-75. pis. 9-12. 

 HARPER, R. A. Die Entwickelung des Peritheciums bei Sphaerotheca Cas- 



tagnei Ber. d. deut. bot. Ges. 13: 475-481. pi. 39. 1895. 

 HARPER, R. A. Sexual Reproduction and the Organization of the Nucleus in 



Certain Mildews. Carnegie Institution of Washington. Publ. 37 : 104. 



7 pis. 1905. 

 NEGER, F. W. Beitrage zur Biologic der Erysipheen. Flora 90 : 221-272. 



1902. 

 REED, G. M. Infection Experiments with Erysiphe graminis De C. Trans. 



Wis. Acad. Sci., etc., 15: 135-162. 1905. 

 REED, G. M. Infection Experiments with the Mildew on Cucurbits, Erysiphe 



Cichoracearum De C. Trans. Wis. Acad. Sci., etc., 15: 527-547. 1907. 

 SALMON, E. S. A Monograph of the Erysiphaceae. Memoirs of the Torrey 



Bot. Club 9 : 292pp. 9 pis. 1900. 

 SALMON, E. S. Further Cultural Experiments with Biologic Forms of the 



Erysiphaceae. Ann. Bot. 19 : 125-148. 1905. 

 SANDS, M. C. Nuclear Structures and Spore Formation in Microsphaera Alni. 



Trans. Wis. Acad. Sci., etc., 15: 733-752. pi. 46. 1907. 

 SMITH, GRANT. The Haustoria of the Erysipheae. Bot. Gaz. 29: 153-184. 



pis. n, 12. 1900. 



This is a family which, according to the most recent mono- 

 graph, includes forty-nine species and eleven varieties of fungi, 



