THE CANADIAN HORTICULTURIST. 



NOTES FROM THE BIOLOGICAL DEPARTMENT OF THE 

 ONTARIO AGRICULTURAL COLLEGE. 



I, Crude Petroleum lixperiments ag^ainst 

 the San Jose Scale. 



Prof. J. B. Smith, of New Jersey, has 

 recently published a bulletin (number 146), 

 dealing with the action oi crude petroleum 

 as insecticide. The results secured by Dr. 

 Smith are interesting-, and should be known 

 to all the fruit-g-rowers of the sections in- 

 fested by the San Jose Scale, for his suc- 

 cesses and failures depend largely on the 

 quality of the crude petroleum used and on 

 the mode of application. 



Crude petroleum varies widely in its com- 

 position, and has no definite meaning in the 

 trade. Crude petroleum as it comes from 

 the well, Dr. Smith says, does comparatively 

 little injury to vegetation unless the appli- 

 cation is very excessive or long- continued, 

 but crude oil composed of mixed crude and 

 distillate is decidedly harmful. For orchard 

 spraying the crude petroleum should have 

 a specific gravity of 43° on the Beaume oil 

 scale at a temperature of and any oil which 

 registers less should not be used, for injury 

 will be done to the trees. If these conclus- 

 ions are correct, then Dr. Smith has done a 

 real service to fruit-growers who purpose 

 using the crude oil against the scale. 



The Bulletin also records cases of decided 

 injury to trees by the application of crude 

 petroleum, but such results are accounted 

 for by the use of oil registering lower than 

 43 degrees. 



Regarding the action of crude oil, Dr. 

 Smith says that the tree should be dry when 

 the oil is applied, though it may be cloudy 

 and rain immediately thereafter. "The 

 best time to spray peach trees is while the 

 buds are fully dormant, not when they are 

 about to waken into life and growth. Apple 

 buds are very well protected, and are rarely 

 hurt unless the oil is in excessive quantitv. " 



Spraying is best done with a vermorel 

 nozzle adjusted so as to give a fine mist, 

 and no more oil should be used than sufficient 

 to moisten the surface thoroughly. Half a 

 pint will be enough for an average size peach 

 tree. The oil may be applied undiluted, or 

 in a mechanical mixture with water by means 

 of an emulsion sprayer. Dr. Smith "prefers 

 the undiluted form because it is then known 

 exactly what has been done." Spraying 

 should be done on mild days, for the oil 

 when cold "becomes less fluid, is not so 

 readily sprayed, does not penetrate well and 

 is less effective." 



2. Recent Books on Mushrooms and 

 Toadstools. 



During the past few years great activity 

 has been shown in the collection and study 

 of mushrooms and toadstools, usually called 

 fleshy fungi. As a result oi some of these 

 studies three important works have been 

 published lately all of which will tend greatly 

 to a better and more satisfactory knowledge 

 of these very interesting plant forms. 



The first work which deserves mention is 

 Underwood's Moulds, Mildews, and Mush- 

 rooms, a small book published by Henry 

 Holt & Co., New York, 1899. The fleshy 

 fungi are treated concisely, and tables are 

 given for the purpose of identification of the 

 edible, suspicious and poisonous species. 

 Illustrations are absent, a feature of decided 

 demerit. The book serves as a good intro- 

 duction to fungi in general, and to fleshy 

 forms in particular. 



The next work Mcllvaine's One Thousand 

 American Fungi, published by Bowen-Merrill, 

 the present year, 1900, is a more pretentious 

 book, containing beautiful illustrations of 

 the common fleshy forms, and carefully pre- 

 pared botanical descriptions of the various 

 species. Several pages are devoted to the 



