Periodical Literature. 485 



is accentuated, since one race may in a given locality be quite 

 worthless which elsewhere would have good value. 



The forms differentiate by morphological characteristics of 

 needles, buds, cones, ramification, growth, probably of root- 

 system, as well as different response to soil and climate. The 

 author confines himself mainly to a discussion of crown and shaft 

 form. 



The pictures gathered from many points of the botanical field 

 and different situations exhibit the variety. They show that the 

 old pines from southern and middle Scandinavia, from Livland, 

 but also from the Black Forest, those from the Bavarian Alps 

 and the mountains of southern France are alike in the straight 

 erect bole which holds out to the very tip like a spruce, with thin, 

 relatively short branches and short stout, vigorous needles — so 

 much like spruce in form that in a picture they are apt to be con- 

 founded. Quite different is the short stout tree of the Mark 

 Brandenburg with an immense, rounded off, paraboloid or hemis- 

 pherical form, with stout, gnarly, often bent and broken branches 

 and bushy long needles. While in each locality one or the other 

 form is prevalent, the most varied forms can and do occur in the 

 same locality. The greatest variety of form is to be found in the 

 lowlands with mild climate, where only rarely here and there the 

 desirable spruce-like form occurs. The severer the climate, the 

 farther north and northeast, the higher in altitude the more 

 slender, spruce-like becomes the form. Since, however, every- 

 where different forms are found together, these cannot be varie- 

 ties or races specially adapted to the site, but for each site a form 

 developes from the variable species, which is specially favorable ; 

 hence where all ecological conditions are favorable, the greatest 

 variety of form is found ; where broad crowns are an advantage, 

 these will prevail, and where this broad form is disadvantageous 

 as in the snowy mountains and northern latitudes, this form will 

 be scarce. The influence of snow pressure in causing form is 

 argued at length; on the other hand Mayr's dictum, that the 

 higher air humidity on good soils causes trees to grow not only 

 higher but more slender, is combated as regards the latter propo- 

 sition. 



The spreading habit, to be sure, can to some extent be corrected 

 by education — dense planting and by mixing with spruce, pro- 

 vided the latter is as well fitted to the locality as the pine. On 



