135 



model. The little animal, which before was stretched 

 out in a strait line, becomes more and more curved. 

 If is successively clothed with muscles, tendons, flesh, 

 and feathers, and in eighteen or twenty days is a 

 perfect chick, 



13. If the chick pre-existed in the hen, it is probable 

 the horse pit-existed in the mare. This would be 

 more than probable, if it could be demonstrated that 

 the young of viviparous animals are enclosed in eggs, 

 and that ail the difference between viviparous and ovi- 

 parous may be reduced to this, that the former are 

 hatched in the belly of their mother, and the latter 

 alter their issuing i'rom it. 



On the two sides of viviparous females there is a 

 body resembling a bunch of grapes, whose berries are 

 bladders full of a limpid liquor : these are the ovaries ; 

 they comnmn cate with the matrix by two canals, which 

 they call tubes. The prolific "liquor penetrates into the 

 matrix, and passes through the tubes into the ovaries, 

 Thus fecundation is yerfonned. Fetus's have more 

 than once been found iii (he ovaries i I self. Nay more, 

 there has IK en found in a vesicle of the ovary a com- 

 plete fetus sketched iti miniature. 



The vesicles of the ovary are real eggs, which, after 

 fecundation, descend through the tubes into the matrix, 

 and are. there in some measure brooded on. In a- short 

 time they send forth small roots, which- convey the nour- 

 ishment to the embryo. The suppleness of their mem- 

 branes admits of their extending and making way for 

 the growth of the little animal. It is true, the growing 

 of eggs is not familiar to us; but the history of insecfs 

 furnishes us with many examples of it. It even ex- 

 hibits to us insects that are at one time viviparous, nil 

 another oviparous. The young were in that case at 

 first lodged in e*r?s ; sometimes the mother lays her 

 eggs,, and at another brings forth living young ones, 

 which were hatched from these eggs whilst they were 

 yet in the matrix. 



It is therefore the same with respect to the vesicles of 



