ON GENERATION. 235 



the course of the third day, we proceed to the Third Stage, 

 which falls to be considered after the lapse of three days and as 

 many nights. Aristotle 1 says : " Traces of generation commence 

 in the egg of the hen after three days and three nights [of in- 

 cubation] ;" for example, on Monday morning, if in the morning 

 of the preceding Friday the egg has been put under the hen. 

 This stage forms the subject of the third figure in Fabricius. 



If the inspection of the egg be made on the fourth day, the 

 metamorphosis is still greater, and the change likewise more 

 wonderful and manifest with every hour in the course of the 

 day. It is in this interval that the transition is made in the 

 egg from the life of the plant to the life of the animal. For 

 now the margin of the diffluent fluid looks red, and is pur- 

 purescent with a sanguineous line, and nearly in its centre there 

 appears a leaping point, of the colour of blood, so small that at 

 one moment, Avhen it contracts, it almost entirely escapes the 

 eye, and again, when it dilates, it shows like the smallest 

 spark of fire. Such at the outset is animal life, which the 

 plastic force of nature puts in motion from the most insig- 

 nificant beginnings ! 



The above particulars you may perceive towards the close of 

 the third day, with very great attention, and under favour of a 

 bright light (as of the sun), or with the assistance of a magni- 

 fying glass. "Without these aids you would strain your eyes in 

 vain, so slender is the purple line, so slight is the motion of the 

 palpitating point. But at the beginning of the fourth day you 

 may readily, and at its close most readily, perceive the "palpi- 

 tating bloody point, which already moves," says Aristotle, " like 

 an animal, in the transparent liquid (which I call colliqua- 

 meiitum); and from this point two vascular branches proceed, 

 full of blood, in a winding course" into the purpurescent circle 

 and the investing membrane of the resolved liquid; distributing 

 in their progress numerous fibrous offshoots, which all proceed 

 from one original, like the branches and twigs of a tree from 

 the same stem. Within the entering angle of this root, and in 

 the middle of the resolved liquid, is placed the red palpitating 

 point, which keeps order and rhythm in its pulsations, composed 

 of [alternate] systoles and diastoles. In the diastole, when it has 



1 Hist. Anira. lib. vi, cap. 3. 



