ual reproduction.-Coupling.-Birth of the sexes.-Hermaphrodism and pa

In the first living forms there are neither sexual organs nor differentiated sexual elements. The animal reproduces itself by scis

ps. Budding is common to protozoaires, infusoria, c?lenterata, to fresh-water polyps and to nearly all vegetables. A third primitive mode, sporulation, consists in the

eunions of simple primitive beings which have differentiated themselves and still retained a solidarity, sharing the physiological work between them. Colonies of protozoaires are formed of individuals having identical functions, living in perfect equality, despite the hierarchy of position;

much more than a convenience for memory. The nomenclature stops, as does the progression, at a certain moment, for the evolution has its limit, its finality, as does even the milieu in which life continues to evolve. One might say that heaving up from the obscure vital centre, the new animal-shoots branch upward until they knock their heads upon an ideal or imaginary roof which prevents any further climbing. This is the death of the species, and Nature contemptuous

longs to the artizoaire series: a head, belly, back, bilateral symmetry; to the vertebrate branch: internal skeleton, cartilaginous and osse

neither segmentation nor budding can take place, at least not indefinitely. In sum, the reproduction of beings is always sexual; only in the one case, the protozoaires, it is produced by non-differentiated elements; and in the other, the metazoaires, by differentiated elements, a male and a female. If one clips off bits of a sponge, a hydra, one obtains as many new individuals, which when they have grown one may again divide, and so on repea

cellules A unite with cellules B (macro-nucleus and micro-nucleus among protozoaires; ovule and spermatozoid among metazoaires), in order that the organism may usefully exteriorize a part of its substance. When the too complex organism has lost the primitive faculty of segmentation, it makes use, directly, to reproduce itself, of certain cellules diff

s, for example up to the moment where it disappears in the mollusk series, whereof some possess so luxurious a love-organism. The simple and very naive form, that in which the sperm and the eggs are produced simultaneously inside the same individual, is found only in inferior organisms. Normal parthenogenesis belong equally to summary and to complicated animals, to wheel-animals and to bees. Among arthropodes, that is to say among insects in general, the sexes are always separate, save in certain tardigrade arachnids, but these are the ones which offer the finest cases of parthenogenesis, generation without aid of the male. The ter

18 degrees (centigrade); above that the eggs hatch out males. Between the periods of coupling there are long stretches of virgin-birth, nothing but females producing females, until the temperature permits a male hatch. In two years the plant louse runs through ten or twelve parthenogeneses; in

genius, celebrated also for his observations of hydra, threw out the idea: Who knows whether a coupling of these lice does not fecundate them for several generations? He had disco

were capable of reproduction, it would be but for a limited period. This provoked parthenogenesis is neither more nor less interesting than the normal. It is doubtless abnormal, but abnormal parthenogenesis is not infrequent in nature; eggs of the bombyx, of star-fish, and of frogs, hatch sometimes without fecundation, and very probably because they have accidentally come up against the very stimulant which the excellent experimenters have lavished on them. Whether sperm acts as an "excitant" or as fecundator, the action is no easier to understand by one label than by another. The queen bee lays both fecundated and non-fecundated eggs; the first hatch female, the second in

tle males are called spermatozoides, and the little females, ovules; it is between these new creatures, between these spores, that the fecundating union occurs. One then observes that a and b resolve themselves into a third animal x, which by natural growth becomes either A or B. Then the cycle begins again. The union between A and B is merely a preparation; A and B are nothing but channels carrying a and b, carrying them often far beyond themselves. Like t