EXPERIMENTS ON THE GERMINATION OF CONIFER SEEDS. 25 



are beneficial, while others are apparently ineffective, in some 

 cases actually harmful, e.g. acetic acid. 



Of various preliminary treatments not involving soaking of 

 the seeds, mention need be made of one only, viz. the use 

 of red lead. The seeds were rolled in red lead till coated, 

 having been previously damped with methylated spirit to 

 enable the powder to adhere. This method was tried for 

 Norway spruce, Sitka spruce, and larch, and the results compared 

 favourably with the control. Probably, therefore, treatment with 

 red lead is not harmful, and it does not seem to delay germina- 

 tion. 



The general results suggest further lines of enquiry, dealing 

 with much larger numbers, under actual nursery conditions. 



Finally, reference may be made to the weights of seeds. 

 Of European larch, altogether 3400 seeds were weighed, in 

 lots of 100 each, totaUing 19-832 grm. The weights of 

 individual samples lay between 0*504 grm. and 0-698 grm. 

 while the average weight was 0*583 grm. 



Of Norway spruce 3400 seeds weighed 29-321 grm., the limits 

 of variation per hundred ranged from 0-818 grm. to 0-927 grm., 

 and the average weight was 0-862 grm. 



The great variation in the weights of each hundred, in 

 European larch at any rate, is probably due to the large 

 percentage of light seed, and the question is thus raised of 

 the advisability of substituting weighing for counting, in 

 preparing seeds for germination tests, i.e. sowing a given 

 weight of seed instead of a given number. 



In conclusion, I must thank Prof. W. W. Smith, Regius 

 Keeper of the Royal Botanic Garden, Edinburgh, for affording 

 facilities to carry out the experiments, and Mr L. B. Stewart, 

 the Plant Propagator, for helpful suggestions, also the University 

 staff at the garden, especially Mr J. R. Matthews and Dr 

 Graham. 



