NOTES AND ABSTKACTS. 537 



Fruits for Cultivation in the United States and Canada. By 



a Committee of the American Pomological Society (U.S.A. Dep. Agr., 

 Bur. PI. Ind., Bull. 151 ; June 1909). — This is a comprehensive list of 

 fruits, from hardy to tropical, recommended for cultivation under the 

 varying conditions of this vast area. It is based upon the deliberate 

 ratings of practical fruit-growers in the various pomological districts in 

 response to some 2,000 inquiries sent out by the Bureau of Plant Industry. 

 It is arranged in tabular form, showing the place of origin of the variety, 

 its form,, size, colour, flavour, quality, use, and season, with various 

 recommendations for the eighteen districts into which these countries are 

 divided for this purpose. It is undoubtedly a very useful and up-to-date 

 publication for intending planters in the United States and Canada, but 

 the authors point out that, owing to the extended range of the districts, it 

 should not be relied upon to the exclusion of local knowledge and the 

 experience of others in the vicinity. — A. P. 



Fruits, Variation Of. By Pierre Passy (Jour. Soc. Nat. Hort. Fr., 

 April 1909, p. 237). — This paper is a further attempt to discredit the 

 ecent theory of possible hybridization between stock and scion in grafted 

 trees. 



M. Passy argues that while the produce of the graft is undoubtedly 

 influenced in several ways by the stock on which it is grafted, such in- 

 fluence is identical both in manner and direction with that exercised by 

 soil and situation. He declares himself not justified, of course, in 

 asserting that means may not be found of producing such hybridization, 

 but is emphatic on the point that, fortunately for horticulturists, it 

 never has taken place yet, and it is still possible to perpetuate varieties 

 uninterruptedly by grafting. — M. L. H. 



Fumigation of Nursery Stock. By J. L. Phillips (Jour. Econ. 

 Entom., ii. (1909), 4, p. 280). — Injury to nursery stock by fumigation 

 with hydrocyanic acid gas has been reported. The author finds this is 

 usually due to too tightly packing the trees in the fumigating house, and 

 under these conditions it is not possible to reach all the trees, so as to 

 completely destroy San Jose scale. The amount of material required for 

 100 cu. ft., the charge to remain an hour, is — 



3 fluid oz. water. 



1 fluid oz. commercial sulphuric acid (sp. gr. 1*83). 



1 oz. fused potassium cyanide. F. J. C. 



Fungi and Environment (Bot. Gaz. vol. xlviii. (1909), No. 1, 

 pp. 1-30 ; with 37 figs.). — Messrs. Stevens and Hall find that important 

 differences are produced in the growth of fungi by variations in the 

 method of culture. The density factor (close or scattered sowing) affects 

 both the size of the colony, the colour and formation of pycnidia. Zonal 

 arrangement is due to the crowding of mycelia, and not to light or heat 

 relations. The use of various chemicals in plate cultivations of eleven 

 fungi affected the colours, size and separation of spores. Light has little 

 or no effect upon the lineal growth of the three fungi tested, but inhibits 

 pycnidial development and produces zonation of colonies. 



