REST PERIOD STUDIES WITH SEEDS II 



Two things seem to be proved by these tests first, that seeds 

 of more than half of the species of plant forms as they occur in 

 Missouri have a pronounced rest period, and, second, that of the 

 species having a rest period, by far the greater percentage are woody 

 forms. In ten instances the dried seeds grew earlier than those that 

 were not dried ; in nine instances those that were not dried grew 

 first, and in three cases the dried and undried seeds grew at the same 

 time. 



It is impossible to say whether the woody species failed to grow 

 because the seed coats were too hard to begin with, or were hindered 

 by reason of having a rest period. Experience with some of the seeds, 

 however, leads to the belief that even though it had been possible to 

 remove the mechanical obstruction, germination would not have taken 

 place for some months. 



REST PERIOD INVESTIGATIONS WITH SEEDS DURING 

 1911, 1912, 1913* 



These investigations were begun in June, 1911, and were con- 

 tinued thruout the summer and early fall of that year. The work was 

 resumed in the spring of 1912, and a vigilant lookout was kept for the 

 first seeds of any species that ripened. Thereafter so far as possible, 

 seeds of all species of wild and cultivated plants growing in the 

 vicinity of Columbia, were gathered. This continued until late in 

 July, when, due to illness on the part of the collector, the work had 

 to be discontinued until October. Such seeds as were still available 

 at that time and later during the fall were collected. During the 

 fall and winter of 1912-13 extensive experiments were carried on 

 with the seeds that had been collected. Some of the last seeds planted 

 were still under observation as late as May 1, 1913. 



During the two seasons these investigations were carried on, al- 

 most 200 species, representing fifty-one orders, were collected. In 

 all more than 900 samples of seeds were planted. The usual number 

 of seeds in each sample was 100; therefore, this part of the seed in- 

 vestigations represents a planting of nearly 100,000 seeds. The most 



* In carrying out the investigations reported in succeeding pages of this- 

 bulletin, the writer wishes to acknowledge, to the fullest extent, the valuable 

 services rendered by Mr. C. C. Wiggans, Research Scholar in Horticulture, (now 

 instructor in Horticulture in the University of Missouri). Mr. Wiggans not 

 only made the large collections of seeds during two seasons, but had charge of alF 

 the details of planting, experimental treatments and observations. The collec- 

 tion and proper classification of the large number of wild species of seeds alone 

 required a vast amount of patience and devotion to the work. Without this 

 expert assistance, it would have been physically impossible to carry the investi- 

 gations thru on so large a scale. 



