280 Scldvely — Contributions to the Life History of 



Having learned by the autumn of '96 that there was more 

 than one variety of aerial seed, efforts were made to ascer- 

 tain their respective powers of germination. In the case 

 of type {a) the percentage ranged from naught to twenty. 

 With seeds of type (b) the same percentage variation was 

 obtained. But filing in each case raised the percentage 

 to seventy. Seed of type (</), (found only during the 

 winter) all germinated within six weeks, if planted imme- 

 diately after being removed from the pots. If allowed to 

 dry, results were no better than those previously mentioned, 

 but with these also, filing raised the percentage. 



Very satisfactory results have been obtained by germinat- 

 ing between layers of moist flannel, kept near steam pipes 

 (temperature of course quite high). Within four or five 

 days many had germinated ; at the end of two weeks there 

 was a well-formed stem and root. All terrestrial seeds re- 

 sponded quickly to this treatment, whether legumes or seeds 

 only were used. Unfortunately this method was not tried 

 until after January 1, 1897, so that I cannot say whether it 

 would be possible to shorten the supposed resting period or 

 not, had the experiment been made in the early autumn. 



With all seeds a temperature of 28 to 30 C. is essential 

 for rapid results. 



It would seem from the above data, that it is rare indeed 

 for terrestial seeds to fail to reproduce the species. 



Aerial seeds were likewise placed under the above con- 

 ditions; germination was much slower than for terrestrial 

 ones. Type (a) gave 2 per cent. ; but with 90 seeds of type 

 (b), not one germinated. 



Some aerial seeds gathered in '94, gave results but little 

 different from those of '95, when subjected to similar con- 

 ditions at the same time. 



Doubtless the peculiar structure of the seed-coats of the 

 aerial ones is an obstacle to their more general germination. 

 In nature, few, if any of these are likely to produce plants 

 in the succeeding spring. 



The seeds of type (b), while in general appearance and 



