202 PHIL RAU AND NELLIE RAU 
females some lived a considerable time after all eggs were depos- 
ited, others died retaining many eggs although they had ample 
time to completely oviposit, and still others died in the midst of 
ovipositing. In 1910 it was found that there was absolutely no 
relation between completeness of oviposition and (1) long life, 
(2) the longer or shorter time spent in copulo, or (3) the age of 
the insects at mating. The mated females, however, oviposited 
more completely than the unmated ones, although they had less 
time to devote to it owing to the long time spent in mating. 
In considering whether or not the length of life is an adapta- 
tion for the good of the species, the completeness of oviposition 
seems to be a factor worthy of attention. The discoveries in the 
relation of long life to completeness of oviposition, as well as the 
long, useless life of the males, do not seem to substantiate this 
theory. 
CONCLUSION 
* 
When the facts gleaned from these observations are compared 
with the various theories which have been advanced to account 
for the duration of life, one becomes conscious of the fact that 
much direct work must be done before any broad generalizations 
can be applied. Very little is accurately known of the normal 
ages of the different members of the animal and vegetable king- 
doms, and still less on the relation of longevity to reproduction— 
why it is that one organism lives for a certain period while another, 
which may mature in the same length of time, or may attain the 
same size, or live in the same environment, attains an entirely 
different age. 
Weismann, as we have already stated, thinks that the dura- 
tion of life is regulated solely by the needs of the species, and that 
this came about through natural selection. Eimer hints about 
the inheritance of acquired characters. Morgan seems to think 
that the problem of the duration of life is one for physiological 
investigation, but goes on cautiously to mention the mutation 
theory. Thus it continues, each man finding in the duration of 
life a conformity to his own already formulated theories. Whether 
it is a subject to be considered in any theory of evolution 
