160 Dr. Haighton’s experimental Inquiry 
mode of scrutiny by experiment, when pointed to one object, 
conferred immortality on his name ; but when directed to an- 
other, reduced him to a level with contemporary reputation. 
Others, perhaps from possessing a greater propensity to 
the subject, have laboured with more success : they have pene- 
trated into the interior recesses of nature, and thence brought 
to view what preceding investigators had deemed inaccessible 
to research. On this view of the subject, our acknowledgments 
are particularly due to the labours of Steno, De Graaf, Hal- 
ler, and others. To Steno and De Graaf we are indebted 
for some important facts on the structure of the ovaries. The 
supposed analogy to the male’s testes is disproved, and the 
vesicular structure, together with a connexion with the ova, 
or rudiments of the new formed animal, fully established. 
From the experiments of De Graaf on rabbits, we learn, 
First. That the ovaries are the seat of conception. 
Secondly. That one or more of their vesicles become changed. 
Thirdly. That the alteration consists in an enlargement of 
them, together with a loss of transparency in their contained 
fluid, and a change of it to an opaque and reddish hue. 
Fourthly. That the number of vesicles thus altered, corres- 
ponds with the number of foetuses, and from these are formed 
the true ova. 
Fifthly. That these changed vesicles, at a certain period after 
they have received the stimulus of the male, discharge a sub- 
stance, which being laid hold of by the fimbriated extremity 
of the fallopian tube, and conveyed into the uterus, soon as- 
sumes a visible vesicular form, and is called an ovum. 
Sixthly. That these rudiments of the new animal, which for 
a time manifested no arrangement of parts, afterwards begin to 
