ORGAN THEBMOGENESIS 



FOLK: The temperature of the running wheel may be a fac- 

 tor here. If the feet are well protected, some species of animals 

 might make out all right, especially the white rat running on the 

 cold metal. The colder it gets, the more this factor might influence 

 the animal. 



HANNON: How did you force your animals to work? We tried 

 this and had all sorts of problems. 



JANSKY: All animals were running in a wheel made from 

 plastic. I attempted to get really maximal values of running and 

 to avoid having them change their position; they could not turn 

 back, for instance. In the axis of the wheel was a load, which 

 could touch and excite the animals forcing them to run. 



HANNON: Did you have any trouble? Dr. Drury in our labora- 

 tory has done similar forced- exercise experiments with the rat 

 in a motor driven screen drum. Other people have tried to make 

 their animals run on a treadmill. We, as well as the individuals 

 to whom I have talked, have encountered a lot of foot and tail 

 injury. 



JANSKY: It depends upon which animal we use for the experi- 

 ments. Some animals are better runners than others. The white 

 rat for example is not a good runner. Many small animals run 

 very nicely, since it is something like a natural movement for 

 them. The species we used really did not need too much force. 



FOLK: We have had a great deal of difficulty forcing exer- 

 cise, and 1 did not quite understand how you got maximum run- 

 ning. You stimulated them, and I would like to hear more about 

 that. 



JANSKY: We used the wheel, and as I said, the wheel was 

 narrow enough to prevent the animals from turning around. The 

 animals, of course, were not restrained. On the axis of the wheel 

 we suspended a load which was freely movable. This load was 

 located behind the animal and would touch him if he ran slower. 

 It was heavy enough to excite the animals. Another improvement 



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