8() PROTECTION OF PLANTS — 1924-25 



A distinct strain of Fomes igniarius — that obtained from poplar — was observed. 

 Chlamydospores are reported in Polyporus balsam eus, P. borealis, P. schweinitzii, 

 and P. versicolor. 



Gordon, W. L. Studies concerning injury to seed oats after smut disinfec- 

 tion. 16th Ann. Kept. Que. Cos. Prot. Plants for 1923-1924: 79-94. PI. 1-4. 

 1924." — This work was carried on in order to determine the factors which cause 

 injury to seed oats after treatment for smut. Three varieties of hulled and one 

 of hull-less oats were used with several diffei^ent treatments and variations of 

 these treatments. The results obtained with each variety are described for 

 each treatment. 



Gussoio, H. T. Plant diseases in relation to certification of seeds. 16th 

 Ann. Kept. Que. Soc. Prot. Plants for 1923-1924: 72-79. 1924.— The impor- 

 tance of the dissemination of diseases by means of seed is emphasized and the 

 lack of precise information concerning such diseases commented upon. 



Gussow, H. T. Seed Potato Certification. 1 — 23. King's Printer, Ottawa 

 1924. — An address before the Select Standing Committee on Agriculture and 

 Colonization outlining the origin and development o^ the present system of 

 potato certification as carried on by the Dominion Department of Agriculture. 

 Reference is made to leaf roll and mosaic, the standards for field and tuber ins- 

 pection are given, and the possibihty of utilizing potatoes for the manufacture of 

 starch and alcohol discuss d. 



Gussow, H. T. Wheat Rust. 1-25. King's Printer, Ottawa. 1924.— 

 The economic importance of rust is pointed out and the salient features of the 

 problem^ — barberry eradication, physiological strains, breeding of resistant 

 varieties and methods of overwintering of lu-edospores are reviewed. The ina- 

 dequacy of the present appropriation for the proper prosecution of the problem 

 is emphasized and increases in the staff and facilities for carrying on this work 

 are strongly urged. 



Gussow, H. T. Report of the Dominion Botanist. Ca^n. Dept. Agric. Exp. 

 Farms Branch for 1923-1924: 1-53. Fig. 1-7. 1924.— The annual report of 

 the Division of Botany dealing with the various phases of investigative work 

 whi3h have been carried on during the year at the central and field laboratories. 

 Among others, there are sections devoted to forest p'athology, potato certifica- 

 tion, raspberry mosaic and leaf curl, cereal rusts, smuts, and root rots, and fire 

 blight. 



Howitt, J. E. A review of our knowledge concerning immunity and resis- 

 tance in plants. 16th Ann. Rept. Que. Soc. Prot. Plants for 1923-1924: 9-24. 

 1924. — Some of the more important achievments in the production of disease 

 resistant plants are recounted and the significance of the terms immunity, resis- 

 tance, apparent immunity, apparent resistance, and tolerance is discussed. 



