432 BOTANICAL GAZETTE [june 



germination of seeds of conifers, and specific reference will be made 

 to a few of the more pertinent papers on the subject. 



It is a matter of common knowledge that conifer seeds germi- 

 nate slowly. It is also well known for several of them that as 

 they grow older the rapidity of germination increases, up to at 

 least the end of the first 6 months after they were gathered. 

 Schwappach (27) states that in the fall seeds of Abies did not begin 

 to show sprouts for 60 days, and required 40 days more before the 

 test could be considered closed. In March they began almost 

 immediately and finished in 20 days. The conclusion is natural 

 that after-ripening takes place, and this, in fact, is assumed by 

 workers who have recently attacked the problem. Hiltner and 

 Kinzel (14), it is true, reasoning from results obtained by treating 

 seeds of Finns Strobus, P. Pence, and P. Cembra with concentrated 

 sulphuric acid, ascribed the delay to coat restrictions. Lakon 

 (20) has made the objection that the tests on which these authors 

 rely were too few and on too small a number of seeds. He repeated 

 their experiments with the same three species of pine, but could 

 obtain no forcing of germination. Untreated seeds took up water 

 just as well as did the treated ones, even though their outer coats 

 were hard. Careful determinations of the amount of water 

 absorbed by untreated seeds of Pinus sylvestris, P. Strobus, P. 

 Pence, and P. Cembra showed that all of them reached nearly the 

 maximum in 24-48 hours. Increases in weight after that time 

 were practically negligible; hence it is clear that such seeds cannot 

 be considered "hard-coated" like the seeds of legumes. More- 

 over, the cutting test, applied to these seeds, showed that all of 

 them were damp, that is, had absorbed water. Increases in weight, 

 therefore, were not due to a few easily swelling seeds. From these 

 results Lakon concludes that conifer seeds are not, strictly speak- 

 ing, "hard-coated," and that delay is due to conditions within 

 the embryo. 



Although Lakon found concentrated sulphuric acid ineffective, 

 Correvon states, in a paper published somewhat earlier, that 

 weak acid (0.25 per cent acetic or 2 per cent phosphoric) increases 

 the germination of seeds of Juniper its Cairns. 



Schwappach recommends cold storage for 14-30 days (he does 

 not say how cold) for seeds of Pinus Strobus, followed by a germi- 



