PERIODICA!, I^ITERATURE 803 



it, together with Corsican and Scots pine, is particularly susceptible. 

 Young plants attacked by the fungus should be grubbed up and burned. 

 The usual distinguishing features of the rot and fructifications are 

 noted. C. J. H. 



Conifer Heart Rot. Forestry Commission, Great Britain, Leaflet 5, 5 pp., 3 

 figs., 1921. 



Mayr's law, that a given species needs less 



Crotvn Form and light in a warmer climate, and more light in a 



Tolerance cool climate, is not entirely true. Several trees, 



notably ihe Scotch pine, spruce, larch, and oaks, 



increase in tolerance eastward and northward from western Germany, 



and are also more tolerant at the higher elevations than on the plains. 



There appears to be a fairly constant relationship between tolerance 



and form of crown, not only for the species mentioned but also for 



others, such as the birch, aspen and Austrian pine. Toward East 



Prussia and western Russia the crowns become narrower, the trees 



Stand closer together, their' boles are more cylindrical, and height 



growth is more rapid. Moreover, in contrast to conditions prevailing 



in western Germany, natural reproduction is abundant under the shade 



of the old stands. W. N. S. 



Rubner. Baumkronenform tmd Schattenfestigkeit. Forstwiss. Centralbl., 

 42:249-258, 1920. 



Summarizes the results of experiments in fer- 

 Nitrogen Fertilizer tilizing spruce nursery stock, carried on during 

 Experiments the 11 years 1907-1917. Full fertilization (pot- 

 ivith Spruce ash, basic slag, and nitrates) applied to 2-year 

 transplants resulted in greater height growth 

 than in the case of those which were fertilized only partially (nitrates 

 only) or not at all, and the effect persisted, although to a less degree, 

 with another application of the fertilizers when the trees were trans- 

 planted at 4 years of age. On the other hand, the fertilized trans- 

 plants, set out in the open without fertilizer when 4 years old, grew 

 more slowly than those which had not been fertilized in the nursery 

 bed, and at the end of the eighth year had lost their early gains and 

 were shorter than the partially or not fertilized ones. Relative weight 

 of root-systems was less in case of complete fertilization, but needle 

 weights were about the same. The foliage of fertilized plants was 



