FUNCTION IN PLANT LIFE 13 



is its skin or rind of very high resistance, and when a 

 turnip is divided as in the illustration given it soon, 

 especially if kept in a dry place, becomes unfit for food. 

 Unlike some other vegetables, such as the potato, it does 

 not appear to be provided with the means of forming fresh 

 insulating material upon the cut surface, with the result 

 that it dries up, and, not being able for that reason to 

 absorb charge from the air, loses its electrical activity and 

 degenerates into a spongy, fibrous, and inedible mass. If, 

 however, it is kept in a moist condition it retains capacity, 

 or power of absorption of electricity from the air, and can 

 be preserved for a longer period of time. This was ascer- 

 tained by cutting turnips in halves. Figs. 10 and 11 show 

 the halves of two turnips taken from the same bunch. That 

 given in elevation was kept under water for ten minutes 

 three times daily, while the other (sectional plan) was left 

 untouched ; both being subjected to identical atmospheric 

 conditions. In the same figures we have the two halves 

 of the turnip in elevation. These were treated as above, 

 and in both instances were sketched after an interval 

 of eight days. They call for no further comment from 

 me. 



THE CARROT AND PARSNIP. 



Fig. 12 sufficiently illustrates the electrical structure of 

 these vegetables, but attention may be drawn to the fact 

 that the roots are connected directly with the negative, 

 and that the central positive system is insulated or pro- 

 tected from the former in the manner shown. If these 

 vegetables are divided in the middle, lengthwise, the 

 negative can be separated from the positive portion with 

 the fingers, leaving the latter exposed as a tongue and 

 exhibiting the former encircled by root-filaments. 



