14 Proceedings of the Newport Natural History Society. 
and relationship of the animal and vegetable world as at 
present constituted. Put in its simplest form Darwin’s theory 
was that all living beings on the surface of the earth have 
descended from a primordial animalcule through successive 
stages by the operation of three general laws, to wit: hered¬ 
ity, variation, and natural selection, or the survival of the 
fittest. 
By the law of heredity offspring are like their parents; 
but while this is true as to the essential characteristics of 
the offspring they usually vary more or less, not only from 
their parents, but from one another, in many minor par¬ 
ticulars. It is well known that all animals and plants tend 
to increase in a geometrical ratio, so that, unless some check 
had been put upon production life would be impossible. 
For example: One of the flesh-flies, Musca carnaria , pro¬ 
duces 20,000 larvae. In the pupa stage each parent fly 
would be increased ten thousand fold in a fortnight. Sup¬ 
posing that this propagation went on unchecked for three 
months at the end of the summer there would result 
1,000,000,000,000,000,000 such flies for every parent fly. As 
with insects so with every other class. The number of 
those destroyed vastly exceeds the number which come to 
maturity, and hence in so many cases the provision for the 
perpetuation of the individual and of the race is made on 
such a magnificent scale. 
Since then there are so many more beings born than 
can find sustenance there must be a continual struggle for 
existence, those that are stronger killing those that are 
w T eaker, while millions perish in the egg through accidents, 
through physical agencies, and by being devoured by other 
animals. 
Here comes in the law of natural selection. Darwin 
argued that if in the variation of any individual the devi¬ 
ation from the parent form was such as to give it an ad¬ 
vantage in the struggle for existence, it will survive, while 
less favored individuals, or those in which the variation 
is disadvantageous to its existence, will be destroyed. By 
