SHORT ELECTRIC WAVE RADIATION 549 



generated in the treated material was not in some way the cause of the 

 effects observed. 



Most biological material does not lend itself readily to such a delicate 

 test as the above, but it occurred to the writer that in the incubation of the 

 chicken's egg there might be possibilities of a more favorable comparison 

 of the effects of the direct application of heat and high frequencies. In 

 this case the essential technique consisted in substituting the heating 

 effect of the field during a part of the natural incubating period. Provid- 

 ing the technique was properly handled, it was thought that if high 

 frequencies had no other effect than that of pure heating, no change 

 would occur in the natural development of the chick. 



In this experiment unpublished and incomplete data indicate that 

 treatment of very early stages (before or during the formation of the 

 primitive streak) in the chick has no apparent effect on development. 

 Treatment of the chick embryo at the 48-hr. stage or later, however, 

 has a marked effect on development. The action of the field in 76 per 

 cent of the cases studied was that of a delayed lethal result. Macroscopic 

 and microscopic study of the embryos failed to reveal the cause of this 

 delayed lethal effect. 



The average time of treatment in this experiment was about 10 hr. ; 

 and, since every possible precaution was taken during this time to main- 

 tain by the action of the field the correct degree of incubation tempera- 

 ture, this is thought to very strongly indicate that external heat and 

 high-frequency fields are quite different in their action upon living 

 material. 



It is probable that the embryos exposed to the field while in very 

 early stages are not affected because of the more or less indifferent nature 

 of the tissue present before or during the formation of the primitive 

 streak. At 48 hr. or later nervous tissue predominates and it may be, as 

 indicated by other experiments in this paper, that this tissue was in some 

 way injured. The injury was not, evidently, such as to kill the embryos 

 immediately but was sufficient to stop development after a few days. 



CONCLUSIONS 



The experimental results of all investigators clearly demonstrate that 

 the electric field is capable of profoundly modifying living tissue, and use 

 of this source of energy has not only produced many interesting biological 

 effects but has opened a number of new lines of investigation. 



Synthetic fevers can be generated in the animal body, affording a new 

 and well-controlled method for the experimental study of fever physiology 

 and of the temperature-regulating mechanism. 



Its possible utility in studies of growth is demonstrated by its power 

 to bring about acceleration in the germination of seeds. 



