40 EX VI RIB US VIVIMUS. 



if they possess it after their last moult, if they ever 

 have a last moult. Salamanders and Crustacea belong 

 to the same category as fish. 



A second lot of organisms die at once upon the 

 setting in of reproduction by the rapid abstraction 

 of the matter of life contained in the eggs and 

 sperm. The Protozoa are typical of this group, for 

 in them the formed matter of the organism is all 

 that remains after reproduction, the entire mass of 

 the germinal or living matter being used in repro- 

 duction. Hence there is no after-life, no down-hill 

 run. It is the same with insects and with annual 

 plants ; so much of the living matter is taken that 

 they have not power to recover the loss ; even assimi- 

 lation is stayed. The animals of the former group 

 of small expenditure could recover their generative 

 loss, not being called upon simultaneously^ in other 

 directions. 



A third group have the procreative subtraction 

 coming on late. It checks growth and finally stops 

 it, but it is so moderate as to leave the organism 

 enough living matter to go on with, and life ceases 

 only when the living matter is so far reduced as to 

 be unable to keep the existing structures in adequate 

 repair, or provide sufficient material for the neces- 

 sary outlays of force. Such cases are presented 

 by mammals, birds, and possibly some trees and 

 shrubs. 



It may not be out of place here briefly to state 



