The Division of Labor. 35 



The vast amount. of reproductive material pro- 

 duced and apparently wasted in the lower life is 

 one of the most striking facts to the student of 

 nature, and it was long before the significance of 

 this tremendous over-fertility was understood and 

 found to play a very important part in the develop- 

 ment of life. 



Oftentimes in the lower though complex forms 

 of life the parent literally resolves its whole sub- 

 stance into reproductive material, the maturing of 

 this material causing the death of the parent; for 

 instance, in certain very low forms the parent be- 

 comes a mere shell to hold the progeny, and when 

 they mature bursts open to free them, and thus 

 expires. This is the case with the simple Ortho- 

 nectid which, when mature, is little more than a 

 cup of eggs. In certain forms of worms the female 

 breaks up upon liberating the egg-cells, and even 

 as high as the insects the parent is in some cases 

 sacrificed by the development of offspring. 



Offspring is in all life but a portion budded ofT 

 from the parent; sometimes, as we have seen, 

 being a large portion, again but a very small one. 



In the lower forms of life this budding for pur- 

 poses of reproduction may take place in almost 

 any part of the body, but as the creature becomes 

 more complex, reproduction is restricted to certain 

 tissues which are set apart to do that work, and are 

 peculiarly adapted to it. 



As we have seen, both male and female give off 



