intended to give cover to our ignorance. We call nervous system 

 an apparatus consisting of nerve-cells and nerve-filaments. Plants 

 may not have this, but they may have some tissue unlike nerve- 

 tissue which functions as communicator of c&wsgtf-impulses to 

 distant parts. At all events we must infer that Drosera, Dioncea, 

 and others, possess some means of sending messages from one 

 part of their body to another. Lauffen in Switzerland is a long 

 way from Frankfort, yet recently an influence of a dynamo at 

 Lauffen was transmitted to Frankfort, a distance of one hundred 

 and eight miles, with the greatest ease, although in this case also 

 there was no nervous apparatus to do it ! 



It would seem that disturbances may occur either in the cells, 

 before the nervous system is traced out, or after, in the grey matter 

 of nerve-centres. Professor V. Horsley l shows that these centres 

 with their characteristic nerve-cells and nerve-fibres are developed 

 very early in the embryo. 



New types may have had their genesis during embryonic life, 

 while great disturbances in geological periods were going on, and 

 which may have been due to external physical causes acting on 

 the contents of the ovum. 



Sir J. William Dawson 2 says : ' In the Appalachian region of 

 America we have the carboniferous beds thrown into abrupt folds, 

 their shales converted into hard slates, their sandstones into 

 quartzite, and their coals into anthracite, and all this before the 

 deposition of the Triassic Red Sandstones which constitute the 

 earliest deposit of the great succeeding Mesozoic period.' 



This seems evidence enough of the commotion caused by 

 volcanoes and shrinkage, and the changes induced by heat and 

 chemical substances. 



At p. 176 he further says: 'At the close of the Permian 



1 Brain and Spinal Cord, p. 190. 2 Geological History of Plants, p. 175. 



