1 28 Translation from De Graaf 



to me more convenient than the others, we shall in the future use, and 

 we shall call these vesicles ova as does that distinguished man, on 

 account of the exact similitude which they exhibit to the eggs con- 

 tained in the ovaries of birds; for these, while they are still small con- 

 tain nothing but a thin liquor like albumen. That albumen is actually 

 contained in the ova of women will be beautifully demonstrated if 

 they are boiled, for the liquor contained in the ova of the testicles 

 acquires upon cooking the same color, the same taste and consistence 

 as the albumen contained in the eggs of birds. 



It is of no importance that the ova of women are not, like those of 



[^ 181 ] fowls, enveloped in a hard shell, for the latter are incubated outside 



the body in order to hatch the chickens, but the former remain within 



the female body during development, and are protected as thoroughly 



from all external injuries by the uterus as by a shell. 



But before we proceed farther in their description it must be de- 

 termined whether they are found in animals of all kinds and in what 

 way they differ from hydatids. 



We may assert confidently that eggs are found in all kinds of ani- 

 mals, since they may be observed not only in birds, in fishes, both 

 oviparous and viviparous, but very clearly also in qtxadrupeds and 

 even in man himself. Since it is known to everyone that eggs are 

 found in birds and fishes, this needs no investigation; but also in 

 rabbits, hares, dogs, swine, sheep, cows, and other animals which we 

 have dissected, those structures similar to vesicles exhibit themselves 

 to the eyes of the dissectors like the germs of eggs in birds. Occurring 

 in the superficial part of the testicles, they push up the common tunic, 

 [^ 182 ] and sometimes shine through it, as if their exit from the testis is im- 

 pending. 



These ova differ much in animals of various kinds, for we have 

 observed that in rabbits and hares they scarcely exceed the size of 

 rape seeds; in swine and sheep they reach the size of a pea or larger; 

 in cows they often exceed the size of a cherry. 



It must be noted, however, that in these animals, besides the large 

 ova, lesser ones are found, of which some are so minute that they may 

 scarcely be seen, for age and sexual intercourse cause gieat changes 

 in the ova. In younger animals they are smallest, in older animals they 

 become greater, and after coitus they are changed into the globules 

 formerly described, of which one or more are formed, according to 

 the number of embryos produced by the animal. These ova are so 

 [] 183 ] plentiful that we have sometimes seen twenty or more, filled with very 

 clear liquor, in one testicle. Believing that these conditions are found 

 in all animals dissected as yet by us, we asked the eminent Dr. N. 

 Steno if he would deign to communicate to us what he had observed 

 of the female testes in various other animals, of which w^e had not 



