Miscellanea Curiosa.

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'