The first of these seems probable from these three Observations. 1. That some such thing has been so often observ'd by _Malpighius_, in the _Cicatricula_ of an Egg before Incubation, as the Rudiments of an Animal in the shape of a Tadpole, as may be seen in his first, and in his repeated Observations _de formatione Pulli in Ovo_. 2. The sudden appearance and displaying of all the Parts after Incubation, makes it probable, that they are not then actually formed out of a fluid, but that the _Stamina_ of them have been formerly there existent, and are now expanded. The first Part of the Chick which is discovered with the naked Eye, is, you know, the _Punctum saliens_, and that not till three days and nights of Incubation be past; and then, on the fifth day, the Rudiments of the Head and Body do appear. This made Dr. _Harvey_ conclude, that the Blood had a being before any other Part of the Body; and that from it, all the Organs of the _Fœtus_ were both form'd and nourished: But by _Malpighius_'s Observations we find that the Parts are then only so far extended, as to be made visible to the naked Eye, and that they were actually existent before, and discernable by Glasses. After an Incubation of thirty hours, are to be seen the Head, the Eyes, and the _Carina_ with the _Vertebræ_, distinct, and the Heart. After forty hours its Pulse is visible, and all the other Parts more distinct, which cannot be discerned by the naked Eye before the beginning of the fifth day; from whence it seems probable, that even the so early discovery of those Parts of the _Fœtus_ by the Microscope, is not the discerning of Parts newly formed, but only more dilated and extended by receiving of Nutriment from the _Colliquamentum_; so that they seem all to have been actually existent before the Incubation of the Hen. And what _Swammerdam_ has discovered in the transformation of Insects, gives no small light to this; whilst he makes appear in the Explanation of the 13th Table of the General History of Insects, that in those large _Eruca's_ which feed upon Cabbage, if they be taken about the time they retire to be transformed into _Aurelia's_, and plung'd often in warm Water to make a Rupture of the outer Skin, you will discern through the transparency of their second Membrane, all the Parts of the Butterfly, the Trunk, Wings, Feelers, _&c._ folded up. But that after the _Eruca_ is chang'd into an _Aurelia_, none of these Parts can be discern'd, they are so drencht with moisture, tho' they be there actually form'd. Another Consideration is from the Analogy, which we may suppose between Plants and Animals. All Vegetables we do see proceed _ex Plantula_, the Seeds of Vegetables being nothing else but little Plants of the same kind folded up in Coats and Membranes; and from hence we may probably conjecture, that so curiously an organized Creature as an Animal, is not the sudden Product of a Fluid or _Colliquamentum_, but does much rather