SCIENCE TEACHING IN ENGLAND. 
83 
we will sav, become female herrings (and in this matter the 
number of males becomes of secondary importance), and that 
they spawn once a year: in the 
1st year the herring has produced 1,000 
2nd ,, these have produced ... 1,000,000 
1,000 millions 
million millions 
1,000 million millions 
5 5 
3rd 
4th ., 
5 th ,, ,, 
And so on. 
>1 
5 * 
J 5 
IIow many years, think you, assuming (I grant an 
impossible assumption) unlimited food supply, would it take for 
the present seas to be packed full of a solid mass of herrings, the 
displaced water having sought a home elsewhere ? Perhaps 
the cubic capacity of a herring is six cubic inches, if so, 8,000 
till a cubic yard; and though in the second year we shall have 
but 125 cubic yards of herrings, in the third year we shall 
have 125,COO cubic yards, in the fourth year 125 millions, 
and in the fifth 125 thousand millions—that is, upwards of 
20 cubic miles; in the sixth 3 ^ear 20,000 cubic miles, and in 
the ninth year 20 million millions of cubic miles; that is, 
unless my arithmetic is at fault, in the ninth year our solitary 
female herring would have produced a mass of herrings equal 
to GO or 70 times the entire solid bulk of this globe upon which 
we live. Nay, more than this, for we have dealt only with the 
female herrings, and probably an equal bulk of males would bo 
produced; and even then in our calculation we have assumed 
the death, nay more, the disappearance, of all herrings 
excepting those of the present year. This is preposterous, 
you will say, and so it is. But why is it preposterous ? 
Surely not because some proportion of the eggs may be 
infertile or unfertilised, for at the most that would but delay 
for a few years the startling consummation already pour- 
trayed. No ! our premises are impossible; the potentiality of 
herring eggs is limited by the quantity of herring food, 
and starvation would await the overwhelming majority of the 
herrings born, even assuming that starvation does not abort 
the vast majority of the eggs themselves. In this natural 
case of supply and demand, this instance o4 Nature’s 
Malthusianism, this struggle amongst multiplying herrings 
for limited food, two classes of herrings would survive :— 
(1.)—Those of more robust growth, which would by sheer 
force kill off their weaker brethren, and 
(2.)—Those which were capable of sustaining satisfactory 
life on the smallest amount of material. 
Now, although in our actual case we have not to deal with 
herrings alone, but with fish of other kinds as well, the 
