EFFECT OF CLIMATIC CONDITIONS. 13 



All gcrniinatioii tests were made in a dark room where the temper- 

 ature could be comparativel}^ well rej^ulated and was maintained noarh' 

 constant throuohout most tests. (Terminated seeds were removed daily 

 during early stages of the tests and a complete record of the number 

 germinating each day was kept. This is of value in seed testing, 

 because the germinative energy of a seed tells nmch as to its vitality. 

 If seeds have a high vitality, the germinative energy will be very 

 strong, i. e., germination will take place rapidh', giving rise to strong 

 and vigorous seedlings; but if the seeds are of very low vitality, there 

 will be a corresponding retardation in germination, giving rise to 

 weak seedlings, i. e., showing a low germinative energ}-. In most 

 cases throughout this work only the final percentages of germination 

 are tabulated. 



EFFECT OF CL.IMATIC CONDITIONS ON THE VITALITY OF SEEDS. 



It has long since been known that seeds under ordmar}'^ conditions 

 lose their power of germination after the lapse of a few years, or in 

 some cases within a few weeks or months. Many investigators have 

 also learned that the rapidity with which seeds lose their vitality, when 

 stored under ordinary conditions, varies greatly with the section of 

 the country in which such seeds are kept. This loss in vitality is espe- 

 ciall}^ marked in the case of seeds stored in places of relati\'ely high 

 humidity. The rapid deterioration of seeds in localities having a 

 humid atmosphere has become a source of much embarrassment to 

 seedsmen, for they have experienced many difficulties in shipping seed 

 to such places. This is especially marked in the case of seeds sent to 

 growers or dealers in the vicinity of the Gulf of Mexico. Gardeners 

 and planters in that part of the United States are continuall}" com- 

 plaining about the nonviable seeds sent out b}^ seedsmen. Some grow- 

 ers have learned how to guard against this difiicult}" to a certain extent. 

 Zimmer Brothers, of Mobile, Ala. , wrote, on February 28, 1900, con- 

 cerning this matter, as follows: 



During thirty years' experience in market gardening, we have learned that seeds 

 of many hardy plants will not keep in our climate, and when ordering we so time 

 our order that we can plant the seeds as soon as received. If such be impossible, we 

 are very careful to keep the original package unopened until conditions are favorable 

 for planting. If we find it necessary to keep seeds of hardy plants for some months, 

 we put them up on arrival in dry bottles, put on top a bit of cotton saturated with 

 chloroform and cork tightly. We have kept, in that way, cauliflower seed satisfac- 

 torily for twelve months. At the shore seeds keep very badly; one-half mile back 

 they do much better. As a rule seeds of tender plants give but little trouble. 



As far as has been ascertained, no definite experiments have been 

 made with these points in view, and especially with the idea of deter- 

 mining the cause or causes of this deterioration of vital energ}". In 

 order to obtain reliable data on these points, a series of experiments 

 was undertaken in February, 1900, to determine how seeds are affected 



