INTRODUCTION. 
8 
whose very existence and development are a mystery— a mystery, however, which, as far as it has 
yet been unraveled, serves to raise our expectations as to what remains behind. As the telescope 
has revealed myriads of stars beyond the reach of unassisted sight, on account of their distance, 
so has the microscope unfolded countless generations of beings, as much beyond the reach of 
vision, on account of their littleness. When we are told that, in addition to what has been 
previously stated, eight hundred millions of living things may exist in a cubic inch of water, we 
begin to have some faint conception of the scope of our subject, to which is given the name of 
Zoologij^ or the Science of Animal Life. 
THE EQUILIBKIUM MAINTAINED AMONG ANIMAL TRIBES. 
Notwithstanding the variety in size, form, structure, and habits, amidst this profusion of animal 
life, a due balance of power and number is maintained by the influence of species upon species. 
They are destined to act and react upon each other by laws of destruction and renovation, through 
which the proportions of animal existence are preserved in just equilibrium. Multitudes are doomed 
to become the prey of others — whole races are created as though for slaughter; but, great as is 
the loss, the increase is equivalent, in order to the preservation of the species. As I'egards indi- 
viduals, the instinctive means of attack on the one hand, and of self-preservation on the other, are 
such as to equalize their respective chances. Speed, caution, watchfulness, inaccessible retreats, 
the nature of their clothing, and even its color, alike protect the timid and defenceless ; while the 
bolder oppose force to force. Those that are most obnoxious to destruction, are the most prolific. 
Insects, for example, are the common prey of birds and beasts, reptiles and fishes, and often of 
each other ; yet who has ever known their numbers perceptibly diminished ? How great is the 
daily havoc among fishes ! They are the prey of each other : the cachalot, the grampus, the por- 
poise, the otter, and the seal, devour them in multitudes : thousands of oceanic birds find in them 
their natural aliment, whilst man draws them by shoals from the deep ; such, however, is their 
astonishing fecundity, that all these losses are duly repaired. The number of eggs in the roe of 
the codfish has been calculated to be 3,687,760; of the flounder, 1,367,400; of the herring, 
36,960; of the mackerel, 546,680; of the smelt, 38,280; of the sole, 100,360; of the tench, 
383,250. Of an increase by numbers like these, no examples exist ainong the higher classes of 
vertebrata, viz., birds and mammalia : still, the law of the balance of increase and decrease is not 
the less established among them ; hence we justly conclude, that each part of the creation depends 
upon another ; and though, at a single glance, all may seem confusion, it will be found, upon 
mature reflection, that order and due equipoise of parts are the results of a scheme equally well 
adapted and wisely ordained. 
ADVANTAGES OF THE STUDY OF NATURAL HISTORY. 
The advantages attending the study of such a subject as this are obvious. So many animals are 
directly or indirectly subservient to the necessities, pleasures, or luxuries of man, from so many 
does he experience direct or indirect injuries, that a knowledge of them is almost indispensable to 
his existence. Our table, our dress, our household furniture, and a variety of conveniences which 
we enjoy, will remind us, if we reflect for a moment, of a multitude of animals, which, in one way 
or other, are essential to our comfort ; and w^e may, with equal ease, form a catalogue of such as, 
on the contrary, are injurious to our welfare. But, leaving out of the question the necessity thus 
imposed upon us of gaining a general knowledge of natm'al objects, we may observe, that the 
study of natural history is peculiarly fitted for strengthening and enlarging the mind. It disci- 
plines the memory ; it demands the exercise of patient investigation ; it enforces an attention to 
minutiae ; it leads us to detect difi'erences, where none but the practiced eye would perceive them, 
and to trace out analogies, or affinities, which reflection alone can discover. Its aim is truth ; and 
so far, it must be a noble and elevating pursuit. If to correct the imagination, and strengthen the 
powers of reason, be among the advantages attending the study of the exact sciences, not less 
beneficial are the results attending the study of Nature. Yet, independently of this consideration. 
Nature holds out other motives to excite our interest; she asserts her intrinsic value, and, while 
claiming our admiration of her work, speaks of unerring Wisdom and almighty Power. 
