120 ARTIFICIAL REFORESTATION 



rapidly if they are exposed to daylight. The ofl&cial duration for tests 

 has been 30 days for Scotch pine, Corsican pine, spruce, larch and most 

 conifers, willow, alder, elm, hornbeam, maple, oak, and beech, and 42 

 days for maritime pine, aleppo pine, mountain pine, fir, and white 

 pine (P. strobus). 



After these tests are completed note is always made as to how many 

 of the ungerminated seeds are still fresh, but these figures do not enter 

 into the calculation of cultm-al value. 



To obtain the actual sowing value of any seed the product of the 

 coeflScient of purity and the germination per cent is divided by 100. 

 The germinative energy is measured by the number of seeds which have 

 germinated after a fixed period, which is usually 10 days for species 

 germinated for 30 days in all and 14 days for those requiring 42 days to 

 complete the normal tests. 



The following variations are allowed in deciding whether to accept 

 purchases or not : For germination per cent, 5 per cent for species running 

 90 per cent and more; 8 per cent for species less than 90 per cent; purity, 

 2 per cent and 3 per cent; cultiu-al or real value, 6 per cent and 9 per 

 cent. As Fron remarks, "If the cultural value were guaranteed at 80 

 per cent but showed only 70 per cent or less, the seed could be accepted." 

 For American conditions such percentages set too high a standard; they 

 should be at least 10 to 20 per cent less. 



The water content of samples is found by taking 10 to 20 grams 

 (0.3 to 0.6 ounces T.) and maintaining it for three days at a tempera- 

 ture of 105° C. (221° F.). The loss in weight after being dried gives 

 the desired per cent when divided by 100. 



The station record shows how the tests were made, the amount of 

 seed received and actually used, date seed was shipped and received, 

 how packed, and conditions after transport. 



Rtiles for Seed Control. — French foresters have tried to have all 

 sales of tree seeds controlled by the State so that buying would be done 

 on the basis of cultural value rather than on a gamble, but as yet no 

 such regulation is in general force. The proposed rules to govern the 

 analysis and control of forest tree seeds are as follows: 



"Article I. — Name of method of analysis and of control. 

 A. The aim of the analysis and control of forest seeds is as follows: 



1. To centralize everything touching on the study, analysis, and control of 



forest seed. 



2. To contribute to the continuous improvement of collected forest seeds 



sold or utihzed in France, based on the results of authentic samples of 

 different kinds and by researches on the physiologic growth, selection, 

 and variety with the aim of practical results. 



3. To contribute to the study of exotic forest species by experiments carried 



out on the seeds locally and in arboretums and experimental plots. 



