Cuar. XIIL] RE-EXPANSION. 259 
expanded after having caught a fly, so that repeated touches 
of the filaments caused not the least movement; nevertheless 
when similarly immersed, the lobes separated a little. As 
these leaves were inserted perpendicularly into the boiling 
water, both surfaces and the filaments must have been 
equally affected ; and I can understand the divergence of the 
lobes only by supposing that the cells on the lower side, 
owing to their state of tension, acted mechanically and thus 
suddenly drew the lobes a little apart, as soon as the cells on 
the upper surface were killed and lost their contractile power. 
We have seen that boiling water in like manner causes the 
tentacles of Drosera to curve backwards; and this is an 
analogous movement to the divergence of the lobes of 
Dionza. 
Jn some concluding remarks in the fifteenth chapter on the 
Droseracex, the different kinds of irritability possessed by 
the several genera, and the different manner in which they 
capture insects, will be compared. 
