136 PHILOSOPHICAL TRANSACTIONS. [ANNO 1797. 



died with the menses on her; the external membranes of the ovaria are burst at 

 one place; whence I suspect an ovum escaped, descended through the tube to the 

 uterus, and was washed off by the menstrual blood. 



c. The ovum sometimes misses the fallopian tube, falls into the abdomen, and 

 forms the extra-uterine foetus; this sometimes grows to its full size, labour pains 

 come on at the 9th month, the child may then be taken out alive by the Caesarean 

 section; or, dying and wasting, but not putrefying, may remain without much in- 

 conveniency to the mother for many years. 



d. The ovum, though it has gone some way down the fallopian tube, may be 

 arrested in its course and become stationary, and form what is called the fallopian 

 tube case. A remarkable case of this kind is given by Dr. Hunter, in his book on 

 the gravid uterus, where the tube burst, and the mother bled to death. 



e. Lastly, the ovum comes into the uterus, where there is room for its enlarge- 

 ment, and a passage for its exit from the body. 



Explanation of the Figures in Plate 3. 



It was not thought necessary to delineate the whole uterus of the rabbit, as it exactly resembles the 

 uterus of other quadrupeds, consisting of a vagina, common to 2 horns, 2 fallopian tubes, and 2 ovaries. 

 Any one who wishes to see this, may see it in De Graaf 's little book, tolerably well executed for the age 

 in which he lived : but I am more concerned in his first appearances of the ova, than in his general ana- 

 tomy of the uterus of the rabbit 5 and therefore proceed to explain the copy of a plate previously en- 

 graven, 1 9 years since. 



The figures marked 3d day, are ova of the fallopian tube, found after impregnation on that day. The 

 first 3 are of the natural size ; the next 3 are magnified, in the simple microscope. In all of them the 

 chorion and amnion are even now distinct, and in some of them the allantois, as I suspect. 



The figures marked 3£ day, are ova still more advanced ; similar to which I found many in the tubes 

 many in the horns of the uterus. The first 3 are of the natural size; the 2 following are magnified also 

 in the simple microscope. 



The figures marked 4th day, are more enlarged ova in the horns of the uterus, loose, not adhering, 

 capable of being moved from one place to another, after these horns are opened, by the gentlest breath 

 blown through a blow-pipe. 



The figures marked 5th day, are ova of the 5th day; still loose in utero, and still capable of being 

 blown with the gentlest breath from one part to another; they resemble the last in every thing, only that 

 they are larger. The first 3 are of the natural size ; the last 3 magnified, as the former ova. 



The figures marked 6th day, are ova found in the horns of the uterus on that day ; sensibly larger than 

 the preceding ; not adhering, even now, to the internal surface of the uterus, but exactly as the last in 

 this respect. The first 4 are of the natural size, the last 3 magnified as before ; but, as kept some 

 years, the amnion has receded from the chorion to a considerable degree. 



The figures marked 7th day, are ova of the 7th day : the first shows the ovum in its cell in the horn 

 of the uterus, laid open ; the next 3 are similar ova, taken out of their cells, and resembling the former; 

 the last 3 are of the same period, and also removed from the uterus, but magnified by the same micro- 

 scope as the preceding ova. They are seen after having been kept many years, and the secession of the 

 amnion from the chorion is still more apparent and greater. 



The figures marked 8th day : the first shows the foetus now first visible to the naked eye by dropping 

 distilled vinegar on it, in one of the cells of the uterus opened. A little above is seen a cell turgid and 

 unopened ; and below a cell half divided. The next 2 figures, in the same line with the foetus men- 

 tioned, are foetuses of the same period from other rabbits, magnified. They show the rudiments of the 

 vertebra-, and the first appearance of the spinal marrow. The 3d in the same row is also magnified, it 

 shows also the earlier appearances of the 2 hemispheres of the brain. 



