Some people have made a sort of bugbear out of this word _spontaneous generation_, or rather, _spontaneous genesis_.[286] And yet, here is one of these truths to which, we think, we shall be led by the observation of facts and by reasoning. The great harm of examining into the question is to be strangely mistaken as to its bearing, and inclined to restrict its limits. It has, in fact, been said, that every day genital organs are discovered in beings whom it was thought were reproduced spontaneously. This is a specious argument to which Plutarch has long ago done justice. A person, whom he brings forward in one of his books, asks, “Which had the first existence, the egg or the hen?” and concludes that “it was evidently the hen.” Even in treating lightly on this subject,--in making it a familiar conversation, the Greek physician was, however, not mistaken about the importance of the matter. “So that,” answers one of the guests, “with this little question of the egg and the hen, we raise, as with a lever, the great and dark question of the generation of the world.”[287] That the animals which we know all reproduce by eggs, is possible, although it has not been proved, but this is not an important point; we want to know if all the animals which we are able to observe do not remount necessarily, in a more or less direct manner, and at a more or less distant period, to a spontaneous beginning.[288] The difficulty is everywhere the same,--everywhere we arrive at that immense obscurity which envelopes the origin of life on the surface of our planet; but it is essential in every case not to give to the phenomenon of spontaneous beginning any other signification than it ought to have. We must not believe, for instance, that matter is formed by the agglomeration of parts which do not yet live in a perfect being, having already all its organs distributed and proportionate, uniting in one living whole. This would be to cast ourselves on the field of an absolutely improbable hypothesis. Histology teaches us that each animal, its instincts and intellect included, is at a given moment merely a mass of amorphous matter, which, at a later period, will form itself, or in the midst of which will be _spontaneously_ developed an anatomical element, that is to say, an organised body. To admit spontaneous genesis, then, is simply to admit the formation of organic amorphous primitive matter apart from an already living body, at the cost of and in the heart of which can be born the initial anatomical element of one of these animals, very properly called _protozoa_. We can even ask, whether this latent primary life, this atomic life, has not always been the ruling life on our planet.[289] And since, when account is taken of everything, we are almost entirely ignorant of the conditions necessary to the fecundity of any primitive embryo, excepting certain physical conditions of temperature, liquidity, etc.; and as, on the other hand,