EFFECT OF CLIMATIC CONDITIONS. 



21 



ditions, the order should have remained the .same throughout, hut the 

 w'uh vaiiation in atmospheric changes ati'ects ditierent seetls so very 

 diti'erentiy that no uniformity of results can he secured. For example, 

 the conditions prevailing from Fe])ruary until June were nuich more 

 disastrous to the vitality of the tomato and pea than to the "A" sweet 

 corn, watermelon, and lettuce, while the conditions existing from June 

 to November were more injurious to the "A" sweet corn, watermelon, 

 and lettuce. An examination of the table will show other results 

 of a similar nature. During the earlier stages of devitalization seeds 

 undergo a gradual deterioration in vitality, but after reaching a cer- 

 tain stage in their decline there is a comparatively sudden falling otf, 

 and seeds, except perhaps a few of the most persistent, soon cease to 

 show any power of germination. Such factors as these mu3t be taken 

 into account in determining the relative length of time that dift'erent 

 kinds of seed will retain their vitality. But as yet sufficient informa- 

 tion is lacking in order to make any trustworthy attempt to classify 

 seeds in respect to their viable periods when subjected to different con- 

 ditions. Numerous experiments are now under way, with the hope of 

 furnishine- a basis for such a classitication. 



In order to obtain more data as to the influence of climate upon 

 vitality additional samples of seed were sent to Mobile and Baton 

 Rouge, where the}^ were stored under the same trade conditions as f or 

 the former experiment. For these tests only cabbage, lettuce, and 

 onion seeds, put up in envelopes, as for the previous tests, were used. 

 The different packages of seed, placed in paper boxes from which 

 they were not removed, were sent from the laboratory on May 20, 

 1901, and were returned November 26, 1901, the total time of storage 

 being 190 days. The results of these tests are shown in Table VI, and 

 are even more striking than those of the former tests shown in Tables 

 1 and II. 



Table YI.— Relative merits of Mohile, Ala., Baton Rouge, La., and Ann Arbor, Mich., 



as places for storing seeds. 



[Period, 190 days.] 



Table VI shows quite clearly the deleterious action of the warm, 

 moist climate of the Gulf of Mexico on the life of seeds. The onion 

 seed which was stored at Mobile and Baton Rouge did not germinate, 



