Periodical Literature 335 



latter over former statements is ascribed to better practice in seed 

 extraction and storing. 



The combination of per cent of purity multiplied by per cent 

 of germination divided by 100 has been considered to give the 

 use value : a seed of 95 per cent purity and 90 per cent germina- 

 tion gives a use-value of 85.5 per cent. But, it is argued, purity 

 and germinative power are not of equal value, an impure seed 

 of high germination per cent has a higher practical value, than a 

 seed v^rith low^ germination. 



In the regulations for the control station given verbatim in an 

 appendix a formula is given by which the true use-value is 

 expressed, namely: 



_ {R^r){K±k)a 

 ^" Rg-Kg 



in which Rg and Kg the guaranteed, R and K the actual purity 

 and germination, r and k the permissible variation in purity and 

 germination, a the contracted sale price, x the proper price. The 

 permissible variations are for purity 1 per cent in seeds of 97 

 per cent and over, 2 per cent for seeds from 90-96 per cent, 3 per 

 cent for seeds under 90 per cent purity. For germination 2 per 

 cent for seeds over 90 per cent, 3 per cent for 80 to 90 per cent, 

 4 per cent for those below 80 per cent germination. 



The error per cent in tests also is discussed at length. For 

 seeds whose germination lies near 50 per cent, the regulation 

 permits variations of 15 per cent ; but Schwappach thinks even for 

 these a variation of 10 per cent sufficient and for others 5 per cent. 



Die Waldsamenprujiingsanstalt Eberswalde. 2^itschrift fiir Forst- und 

 Jagdwesen, November, 1915, pp. 631-51. 



"A Classification of Thinnings and 

 Classification Increment Fellings," by Howard, is given 

 of Thinnings in considerable detail. 



in India To start with, he divides thinnings into 



(1) ordinary thinnings, (2) crown thin- 

 nings, (3) increment felling. The ordinary thinnings are 

 divided into three groups: (a) light thinnings, (b) moderate thin- 

 nings, (c) heavy thinnings. Crown thinnings are divided into 

 (a) light and (b) heavy, as are also increment fellings. The 



