OF THE foetus; 313 



fggs, would they not fucceed each other accor- 

 ding to the different ftates of perfection of the 

 feveral eggs exifting at the time of impregna- 

 tion ? And would not fuperfoetations be as ire- 

 tjuent as they are rare, and as natural as they 

 are acqidental ? 



It is impolTible to trace the gradual expanfion 

 of the human foetus, as we can that of the chick 

 in the egg. The opportunities for obfervatioii 

 are few ; and all we know of this fubje^t is de- 

 rived from the writings of anatomifts, furgeons, 

 and accoucheurs. It is from colleding all their 

 particular obfervations, and comparing their re- 

 marks with therr defcriptions, that the following 

 abridged hiftory of the human foetus has been 

 compiled. 



Immediately after the mixture of the two fe- 

 minal fluids, it is probable that the whole mate-- 

 rials of generation exifl: in the uterus, upder the 

 form of a fmall globe ; for we learn from ana- 

 tomifts, that, three or four days after conception, 

 there is a fmall globular mafs in the uterus, the 

 grcatefl diameter of which is about 6 lines, and 

 the leaft 4, This globe is formed by a de- 

 licate membrane, which contaitis a limpid li- 

 quor very like the white of an egg. We may 

 already perceive, in this liquor, fome fmall fi- 

 bres, which arc the fnft rudiments of the foetus. 

 Upon the fiirface of the globe there is a net- 

 work of delicate fibres, which extends from one 



or 



