REPORT OF THE SOCIETY 61 



in a sterile glass chimne3\ A wad of absorbent cotton was soaked in sterile 

 water insert ed in the outer end which was then closed with a plug of drycotton. 

 A spore suspension was then, as before, sprayed on the frond, and the inner end 

 of the chimney closed with absorbent cotton. Two days after inoculation 

 numerous lesions appeared over the surface of the frond. These developed into 

 typical spots identical with those originally found. Small bits of the diseased 

 tissue thus produced were externally sterilized and planted in agar. The orga- 

 nism which developed from these lesions was found to be identical with the one 

 first isolated, thereby completing Koch's rules of proof. 



Summary 



1. A hitherto unreported disease of Poly podium sp. has been found in the 

 experimental greenhouse at Macdonald College. 



2. It is characterized by the occurrence of brown, concentrically zoned 

 spots on the fronds and stems. 



3. The pathogen is a member of the Adelomycetes and has been tentative- 

 ly named AUernaria polypodii n sp.. 



4. The conidia measure 24 . 5-70. x 10. 5-19 . 25 u, averaging 40. 3x13 . 6 u . 



5. There is a considerable variation in spore size on different media. 



6. The disease has been experimental h' produced by spraying a spore 

 suspension of A. polypodii on healthy, sterilized fronds. 



Bibliography 



1. ]\Iangin, L. and Vincens, P.- — New genus of the Adelomvcetes. 



Bui. Soc. Mvcol, France 5^:89-97: f.1-7. 1920 



{Abstr. Journ. Roy. Micro, Soc. 257: pt. 4:419. 1921) 



2. Saccardo, P.- — Sylloge fungorum. 1880 et seq. 



3. Stevens, F. L.- — The fungi which cause plant disease. 1921. 



Illustrations 



Fig. 1. — Groioth on steamed rice — 29 day a.— PH. 6.4.. 

 Fig. 2. — Growth on potato agar — 22 days — PH. 6.>>. 

 Fig. 3.- — Habit sketch, {reduced one half). 

 Fig. 4-- — Growth on 2% dextrose agar — 79 days — PH 6.7. 

 Fig. o.- — Growth on Richard's solution agar — 17 days — PH. 5.2. 

 Fig. 6. — Growth on iris leaf juice agar — 10 days — PH 5.9. 

 Fig. 7. — Growth on iris leaf juice agar — 17 days PH 5.9. 

 Temperature in all cases 2'yC. Magnification about 330 x. 



HOW WE MAY INCREASE THE EFFECTIVENESS OF ECONOMIC 



ENTOMOLOGY 



By Geo. A. Dean, Kansas State Agricultural College 



(a synopsis) 



Note. — This paper was read in full at the meeting by Rev. Father Leopold, 

 but a synopsis is given here as the paper is printed in the Journal of Economic 

 Entomology. Feb. 1922, pp. 44-53. 



As the problems of the entomologist have not only multiplied but have 

 become more complicated during the last few years, it is very e\'ident that 



