Chap. XV.] ON THE DROSERACE^. 297 



two points. The rate at which the motor impulse is trans- 

 mitted, though rapid in Diona;a, is much slower than in 

 most or all animals. This fact, as well as that of the motor 

 impulse not being specially directed to certain points, are 

 both no doubt due to the absence of nerves. Nevertheless we 

 perhaps see the prefigurement of the formation of nerves in 

 animals in the transmission of the motor impulse being so 

 much more rapid down the confined space within the ten- 

 tacles of Drosera than elsewhere, and somewhat more rapid 

 in a longitudinal than in a transverse direction across the 

 disc. These plants exhibit still more plainly their inferior- 

 ity to animals in the absence of any reflex action, except in 

 so far as the glands of Drosera, when excited from a dis- 

 tance, send back some influence which causes the contents 

 of the cells to become aggregated down to the bases of the 

 tentacles. But the greatest inferiority of all is the absence 

 of a central organ, able to receive impressions from all 

 points, to transmit their effects in any definite direction, to 

 store them up and reproduce them. 



