REST PERIOD STUDIES WITH SEEDS 53 



support to such a view. Fletcher 2 (1910) reported the same results. 



Electric Stimulation. Many investigators have studied the effects 

 of the electric current on different forms of plant life. 3 Nollet was 

 probably the first person to study the effect of electricity on seeds. 

 Later Specnew subjected different seeds to electric treatment and 

 found that germination was very greatly hastened. Paulin found 

 that the electric current would seemingly awaken life in seeds which 

 appeared to have lost their vitality. Tschinkel showed that certain 

 seeds germinated quicker in a soil thru which an electric current had 

 been passed, but Woolny secured only negative results from the use 

 of this treatment on the seed of summer rye, radish, and rape. 

 Kinney 4 concludes that: "Electricity exerts an appreciable influence 

 upon the germination of seeds and the application of certain strengths 

 of current to seeds for short periods accelerates germination." It has 

 also been reported that a galvanic current of high frequency gives bene- 

 ficial results, while a continued current is detrimental to germination. 5 '' 



Contact Stimulation. Apparently seeds of certain plants, particu- 

 larly seeds of vegetable parasites, will not germinate unless they come 

 in contact with a particular host. Heinricher 6 (1909) studied the 

 germination of seeds of parasites. He found that seeds of Lathraea 

 would not germinate unless they were in contact with their host, 

 and the same was true of the seeds of Tozzia, while Bartschia, a 

 related genus, germinated without being in contact with its host. 



Stimulation of Seeds by Light and Heat. Promsy and Drevon 7 

 found that X-rays increased or decreased the germination of seeds of 

 lentils, wheat, beans, and lupines in varying degrees, depending upon 

 the temperature and exposure. The greatest regularity in the effects 

 was noticed during a rather high temperature when, with a certain 

 exposure adopted as the best, the irradiation always favored germina- 

 tion and accelerated the development of the resultant plants. 



Immaturity as a Cause of Early Germination. Altho green or im- 

 mature seeds usually do not germinate as large a percentage as more 

 mature seeds, yet they are sometimes used because of the earlier devlop- 

 ment of the resultant plants. 8 This is especially true of tomatoes. 



2. Fletcher, Experiment Station Record, Vol. 23, p. 722. 



3. Mass. (Hatch) Agr. Exp. Sta. Bui. 43. 



4. Kinney, Mass. (Hatch) Agr. Exp. Sta. Bui. 43. 



5. Exp. Sta. Record, Vol. 25, p. 26. 



6. Heinricher, Exp. Sta. Record, Vol. 23, p. 628. 



7. Promsy and Drevon, Exp. Sta. Record, Vol. 28, p. 128. 



8. Read, Thesis 1908, University of Missouri. 



