BY PROFESSOR AT THE UNIVERSITY OF LOUVAIN, CORRESPONDENT OF THE INSTITUTE OF FRANCE. WITH EIGHTY-THREE ILLUSTRATIONS. NEW YORK: D. APPLETON AND COMPANY, 549 & 551 BROADWAY. 1876....

“The edifice of the world is only sustained by the impulses of hunger and love.”— Schiller. In that great drama which we call Nature, each animal plays its especial part, and He who has adjusted and regulated everything in its due order and proportion, watches with as much care over the preservation of the most repulsive insect, as over the young brood of the most brilliant bird. Each, as it comes into the world, thoroughly knows its part, and plays it the better because it is more free to obey

The messmate is he who is received at the table of his neighbour to partake with him of the produce of his day’s fishing; it would be necessary to coin a name to designate him who only requires from his neighbour a simple place on board his vessel, and does not ask to partake of his provisions. The messmate does not live at the expense of his host; all that he desires is a home or his friend’s superfluities. The parasite instals himself either temporarily or definitively in the house of his neig

We meet with free messmates in various classes of the animal kingdom. They sometimes mount on the back of a neighbour, sometimes occupy the opening of the mouth, the digestive passages, or the exit for the excreta; at times they place themselves under the shelter of the cloak of their host, from whom they receive both aid and protection. Among the vertebrates, there are few except fishes which merit a place here; it is only amongst these that we meet with species at the mercy of others, and depe

The animals of which we have just spoken usually preserve their full and entire independence; from the time of their leaving the egg, till their complete development, they are subject to no other outward changes than such as belong to their class. If they sometimes renounce their liberty, it is only for a limited time; and they all preserve not only their peculiar appearance, but their organs intended for fishing or for locomotion. It is not thus with those which we are now about to consider; th

In this chapter we bring together animals which live on each other, without being either parasites or messmates; many of them are towed along by others; some render each other mutual services, others again take advantage of some assistance which their companions can give them; some afford each other an asylum, and some are found which have sympathetic bonds which always draw them together. They are usually confounded with parasites or messmates. Many insects shelter themselves in the fur of the

“En plongeant si bas dans la vie, je croyais y rencontrer les fatalités physiques , et j’y trouve la justice, l’immortalité, l’espérance.”— Michelet , l’Insecte . The parasite is he whose profession it is to live at the expense of his neighbour, and whose only employment consists in taking advantage of him, but prudently, so as not to endanger his life. He is a pauper who needs help, lest he should die on the public highway, but who practises the precept—not to kill the fowl in order to get the

This first category of parasites includes all those which are not enclosed, and which live at the expense of others, without losing the attributes and advantages of a wandering life; they are as free as the vulture or the falcon which pursues its prey. We shall not, however, include among them the parasitical kite of Daudin, which tears from the hands of the traveller a piece of the flesh which he is preparing in the open air, nor the small Egyptian plover, which keeps the teeth of the crocodile

We have brought together in the former chapter the animals which live at the expense of their neighbours, without seeking for anything except shelter. They seize their prey as they pass, are nourished by the blood of their neighbours, but never think of establishing themselves in their organs during any period of their life. They are almost as much carnivora as parasites, and only differ from the former class because they spare the life of their victims. They are unlike ordinary parasites, since

We are about to study in this chapter animals which seek for assistance from others while young, and are able to provide for themselves completely when they have grown old. We may compare the hosts which afford them shelter to crèches which receive none except newborn infants. It is generally supposed that animals known under the name of parasites are such as require assistance from their neighbours during all the stages of their existence. [3] This is a mistake. There are very few among them wh

A certain number of parasites establish themselves at first in an animal which serves as a crèche , then in a second which serves as a lying-in hospital. This passage from one animal to another is described under the name of transmigration. In general, the entire crèche with its nurslings passes into the lying-in asylum. The crèche is always represented by an animal which feeds on vegetable diet, which is destined for one which is carnivorous: the lying-in asylum is represented by the latter. Th

In this chapter we bring together true parasites, which may be called complete; they pass every part of their life under the care of a neighbour, and require an asylum the more urgently, since they cannot exist without it. They absolutely need both food and lodging. Not long ago, all parasites were supposed to be dependant during their whole life, and to be incapable of living outside the body of another animal. We have before proved that this opinion was erroneous. We find in this category a gr