in physiology, the act of procreating and producing a being similar to the parent.

According to Aristotle, the male animals contain the principle, and the female the matter of generation; for though both were furnished indeed with a seminal liquor, yet the semen of the males alone was prolific. The moderns, on the other hand, as well those who contend for the system of generation from eggs, as they who adopt that of the animalcules in the male-seed, pretend that females have no such seminal liquor at all, and that what was commonly taken for it was some other animal fluid.

Harvey is of opinion, that all females are furnished with eggs, and that the embryos, or young animals, are formed in the same manner as a chick in the egg of any bird. Generation, according to this celebrated physician, is effected wholly by means of the uterus, or womb; which conceives the fetus by a kind of contagion communicated to it by the male-seed, much in the same way as the loadstone communicates magnetism to iron. This contagion, he thinks, acts not only on the uterus, but is communicated to the whole body of the female, which is altogether prolific; tho' the uterus, he acknowledges, is the only part that is capable of conceiving the fetus, just as the brain is alone capable of forming ideas and notions. Agreeable to this doctrine of Harvey, Steno and other anatomists have pretended to discover certain eggs in the ovaries or testicles of women; which Mr Buffon denies to be the case, affirming, that there are no such eggs to be found in the ovaries or testicles of women.

We cannot enter into a detail of the reasonings for and against the system of generation from eggs; and shall therefore only observe, that its advocates pretend to have discovered eggs in all the females on which they made observations; that the largest of those found in women did not exceed the bigness of a pea; that they are extremely small in young girls under fourteen, but that age and commerce with men makes them grow larger; that there are more than twenty such eggs in each ovary or testicle; that they are fecundated in the ovary by the spirituous and volatile part of the male-seed; that they afterwards are detached and fall into the uterus through the Fallopian tubes; that here the fetus is formed of the internal substance of the egg, and the placenta of the exterior part.

Leeuwenhoek is the author of another system of generation, from animalcules in the male seed. He tells us, he discovered many thousands of these in a drop less than a grain of sand. They are found in the semen of all males whatever, but not in that of females; and are so small, that 3,000,000,000 of them are not equal to a grain of sand, whose diameter is but the hundredth part of an inch. When any of these animalcules gets into an egg, fit to receive it, and this falls into the womb through the Fallopian tubes, the humours which distil through the vesicles of the womb, penetrating the coats of the egg, swell and dilate it, as the sap of the earth does feed thrown into it. The placenta begins to appear like a little cloud, upon one side of the external coat of the egg; and, at the same time, the spine of the embryo-animalcule is grown so big, as to become visible; and a little afterwards, the cerebrum and cerebellum appear like two bladders; and the eyes stand next goggling out of the head; then the beating of the heart, or punctum saliens, is plainly to be seen; and the extremities discover themselves last of all.

These animalcules are of different figures, some like tadpoles, and others like cels. In the semen of a man, and in that of a dog, there have been discovered two different kinds of them, the one supposed to be males and the other females. Some even pretend to have seen animalcules disengage themselves from the membranes that surround them; and that they then appeared perfectly like men, with legs, arms, &c., like those of the human body!

All the advocates for the system of generation from animalcules strongly oppose that from eggs. They contend, that these animalcules cannot be looked upon as the inhabitants of the semen, since they were of greater extent than the liquor itself; not to mention, that no such animals are found in any other liquors of the body; and since females have nothing similar to these animals, they think it manifest that the prolific principle... principle resides in males. When they are asked, to what purpose serves such an immense profusion of human animalcules? they answer, that it is agreeable to the ordinary course of nature, both in the animal and vegetable part of the creation. They likewise strengthen their system, by alleging the many examples we have of similar transformations in the insect-clas of animals, which, from caterpillars and small worms, become winged animals of the butterfly or fly kinds.

By this system, says Mr Buffon, the first woman cannot be said to have contained the whole race of mankind, as being all, according to it, the true posterity of the first man, and in their animalcule state contained only in him. On this principle, he proceeds to invalidate the system of generation from animalcules; for supposing the size of a man to be 1, then will that of one of the spermatic animalcules be $\frac{1}{1000000}$; and as a man is to an animalcule of the first generation in the same ratio that this animalcule is to an animalcule of the second generation, it follows, that this last will be expressed by the fraction $\frac{1}{1000000000000}$. In this manner he computes the size of the animalcules of several generations, all supposed to be living animals, notwithstanding that their minuteness exceeds the power of imagination to conceive; and then tells us, that the system of generation from eggs is liable to the same objections, whereof the detail may be seen in his Hist. Natur. tom. II. p. 157, &c.

As to Buffon's own system, he thinks that every part, both of animals and vegetables, contains an infinite number of organic molecules; that these molecules assume successively different forms, and are put into different motions, according to the circumstances they are in; but that they are much more numerous in the seminal liquors of both sexes, and the seeds of plants, than in other parts; that these organic molecules make the matter of nutrition; that this matter is always active, and tends to organization, forming itself into different shapes, according to the moulds it meets with. When the quantity of this organic matter is but small, as in man, and most large animals, generation only takes place at the age of maturity, and even then the number of animals produced is but small. The case is just the reverse in animals which abound with this matter, as in fishes, and most birds.

With respect to the generation of mankind, the same author thinks it a certain fact, that the male-seed is received into the womb of the woman; and that, for this purpose, it is highly probable the internal orifice opens during the act of coition. The female-seed also makes its way into the womb, where, being mixed with that of the male, they both together contribute to the formation of the fetus; which is either male or female, according as the seed of the man or woman abounds most with organic molecules; and the infant resembles either father or mother, according to the different combinations of these molecules. Both these seminal liquors he thinks equally active in the formation of the fetus, and that they fix and counterbalance each other; the molecules of each parent being thereby determined to form similar parts to those of the individual that furnished them, as the head, trunk, arms, legs, &c. He thinks the molecules proceeding from the genital parts fix themselves first; and that the other molecules arrange themselves successively round these, in the same order which they before occupied in the parent: When a great quantity of the seminal liquors of both sexes is received into the womb, there are formed different spheres of attraction, in different parts of these liquors; the consequence of which is, that several foetuses are formed at the same time.

Nearly a kin to Mr Buffon's system is that of Mr Maupertuis, which he has explained in his Venus Phylique. He observes, that all the variety observable among mankind, may have been accidental at first; but being once established in the constitution of the parents, they become natural to their posterity. To illustrate this, he gives an instance of a sediginary family at Berlin, who had six fingers, or six toes, and frequently both; and that this peculiarity was transmitted equally by the father and mother, but was lost by alliances with those who had but the usual number of fingers or toes.

He farther observes, that most animals, excepting mankind, have stated seasons for procreation; and that the females go with young some a longer, others a shorter time. Mares go from eleven to twelve months; cows and hinds go nine months, as do also women; foxes and wolves, five months; and bitches go only seven weeks; cats nine weeks; and rabbits but thirty-one days. Most birds are hatched in twenty-one days; the canary birds, and some others, are hatched in thirteen or fourteen days. It appears, therefore, that there is an endless variety in the time and manner of the generation of animals.

Whoever reads this short sketch of the different theories of generation that have hitherto been invented, will probably require no other arguments to convince him, that physicians and philosophers are still as ignorant of the nature of this mysterious operation as they were in the days of Noah.

Parts of Generation. See Anatomy, p. 270. Generation of Plants. See Botany, p. 643. Genesis, among mathematicians, signifies the formation or production of some figure or quantity. Genesis, among divines, a canonical book of the Old Testament, and the first of the pentateuch or five books of Moses. The Hebrews call it Berechith, or, In the beginning, these being the first words in the book. The Greeks gave it the name of Genesis, from its beginning with the history of the creation of the world. See Bible. Genet, Gennet, or Jennet, in the menage, denotes a small-sized well-proportioned Spanish horse. To ride a la genette, is to ride after the Spanish fashion so short, that the spurs bear upon the horse's flank. Geneva, a city near the confines of France and Switzerland, on the river Rhone, about sixty miles northwest of Lyons: E. long. 6°, N. lat. 46° 20'. Geneva is a fortified town, about two miles in circumference, situated at the west end of a lake sixty miles long, and twelve broad, called the lake of Geneva.