FEMALE ORGANS OF GENERATION.
An ovarium is the most essential and universal of all the female parts of gene ration. In addition to this, those ani mals which breathe by means of lungs, as well as some fishes, and several white blooded animals, have, also oviducts, (Fallopian tubes, &c.) or canals leading from the ovarium to the uterus : and last ly, those, at least, which are impregnated by a real copulation, possess a vagina, or canal connecting the uterus to the ex ternal organs of generation.
In birds all the parts which we have just mentioned are single. Some cartila ginous fishes have two oviducts ; begin ning, however, by a common opening, and terminating in a simple uterus. The human female, as well as that of many other mammalia, has two ovaria, with an oviduct belonging to each ; a simple ute rus and vagina. The females of this class, in several other instances, possess an uterus bicornis : and in some cases the generative organs are double throughout; that is, there are two uteri, and, at least for some extent, a double vagina.
Ovaria are found in the females of all animals where the male possesses testi cles ; but their structure is in general more simple than that of the latter glands, particularly in the first Blass. These bo dies were formerly called the female tes ticles ; but the term ovary is much pre ferable, as it denotes the function which the parts perform in the animal econo my. For, if the office of these bodies be at all dubious, when their structure is considered in man and most of the mam malia, their organization is so evident in the other classes, that no doubt can be entertained respecting their physiology. It is manifest in all these, that the ovaria serve for the growth and preservation of the germs or ova, which exist in these bodies, completely formed., before the act of copulation. Analogy leads us to conclude that these bodies have the same office in the mammalia ; and thus our ex planation and illustration of this most in teresting part of physiology are entirely derived from researches in comparative anatomy.
Of all the external female sexual or gans in the mammalia, the clitoris is found the most universally and invariably. It exists even in the whale, and probably is wanting in no other instance than the ornithorhynchus. As its general structure much resembles that of the male penis, it contains a small bone in several species, as the marmota citillus, the racoon, lioness, and sea-otter.
A true hymen, or one, at least, which in form and situation resembles that of the human subject, has been observed in no other animal.
The structure and form of the uterus vary very considerably in the mammalia. In no instance does it possess that thick ness, nor has its parenchyma that density nor toughness, which are observed in the human female. Of those which I have dis sected, the simia sylvanus had compara tively the firmest uterus. The two-toed ant-eater came the next in order in this respect. But in the greater number of mammalia, this organ is thin in its coats, resembling an intestine in appearance, and proiided with a true muscular cover ing.
The variations in the form of the unim pregnated uterus may be reduced to the following heads : 1. The simple uterus without horns, (uterus simplex,) which is generally of a pyramidal or oval figure. This is exem plified in those animals, where we have stated that it possesses thick coats. Its circumference in some simize presents a more triangular form than in the wo man : and towards the upper part, in the neighbourhood of the ,Fallopian tubes, there is an obsctire division into two blind sacs, (as in the gibbon, or long armed ape :) this distinction is more strongly expressed in the lori, (lemur tardigradus,) so as to form a manifest ap proach to the uterus bicornis.
2. A simple uterus with straight or convoluted horns (uterus bicornis.) They are straight in the bitch, in the bats of this country, in the sea-otter, seal, &c. ; somewhat convoluted in the ceta cea, mare, and hedge-hog, and still more tortuous in the bisulca.