18 MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 17 



Among the orders to which belong species which germinated read- 

 ily as soon as mature were Gramineae, Liliaceae, Caryophyllaceae, 

 Malvaceae, and Compositae, while those which seemed to have a 

 delayed germination included Cypcraceae, Rosaceae, Anacardaceae and 

 Vitaceae. The fresh seeds of Liliaceae and Leguminosae, as a gen- 

 eral rule, germinated quicker and gave a higher percentage of germi- 

 nation than the dried seeds while the results from plantings of Com- 

 positae and Gramineae were exactly the reverse. These two instances 

 would seem to indicate that the seeds of the various species in an order 

 are somewhat similar as regards their requirements for germination. 



Of the fifty-eight species which were able to germinate at all, 

 nine failed to grow from the first planting (fresh seed), and nine 

 in the second planting (dried seed). Twenty-six of the species that 

 grew germinated more quickly where seeds had been dried, indicat- 

 ing that they have a very short rest period, less than one month in 

 extent. In fact a majority of the species studied seemed to require 

 an interval of rest after maturity before they would sprout. The 

 figures also show that seeds which had been dried for a month ger- 

 minated in a much shorter time after planting than seeds planted 

 immediately after they were collected. This apparently shows that 

 the hindrances to germination due to hardness of the seed coat from 

 drying out are much over-balanced by the beneficial effects on germi- 

 nation caused by allowing the seeds to pass thru a month of dor- 

 mancy before being planted. Seemingly then, the assumption that 

 seeds which fail to grow immediately after maturity are possessed of 

 a rest period is incorrect, as the rest period may set in several days 

 after maturity. In fact the process of maturity itself that is, the 

 loss of moisture by the seed seems to bring on the rest period in the 

 majority of cases. 



The average time required for germination to take place for all 

 species was: for the mature seeds, 22.2 days; dried seeds, 17.8 days; 

 total germination, mature seeds, 33.3 per cent; dried seeds, 40.9 per 

 cent. In twenty-six species the dried seeds gave a higher total germi- 

 nation, while only thirteen species gave the highest percentage of 

 germination where seeds were planted immediately after maturity. 

 The average increase in total germination, due to drying out, was 

 6.6 per cent. In nearly every case the higher percentage of total ger- 

 mination was correlated with the shorter time required for germination 

 to begin. 



Second Season's Work, 1912. The seed investigation during the 

 summer and fall of 1912 consisted of the following experiments : 



