Before Aristotle 15 



membranes arise from the umbilical cord. . . . The structure of 

 the child you will find from first to last as I have already de- 

 scribed. ... If you wish, try this experiment : take twenty or 

 more eggs and let them be incubated by two or more hens. Then 

 each day from the second to that of hatching remove an egg, 

 break it, and examine it. You will find exactly as I say, for 

 the nature of the bird can be likened to that of man. The 

 membranes [you will see] proceed from the umbilical cord, and 

 all that I have said on the subject of the infant you will find in 

 a bird's egg, and one who has made these observations will be 

 surprised to find an umbilical cord in a bird's egg.' 1 



The same interest that he exhibits for the development of 

 man and animals he shows also for plants. 



' A seed laid in the ground fills itself with the juices there 

 contained, for the soil contains in itself juices of every nature 

 for the nourishment of plants. Thus filled with juice the seed 

 is distended and swells, and thereby the power (= faculty 77 

 bvvaiJLLs) diffused in the seed is compressed by living principle 

 (pneuma) and juice, and bursting the seed becomes the first 

 leaves. But a time comes when these leaves can no longer get 

 nourished from the juices in the seed. Then the seed and the 

 leaves erupt, for urged by the leaves the seed sends down that 

 part of its power which is yet concentrated within it and so 

 the roots are produced as an extension of the leaves. When 

 at last the plant is well rooted below and is drawing its nutri- 

 ment from the earth, then the whole grain disappears, being 

 absorbed, save for the husk, which is the most solid part ; and 

 even that, decomposing in the earth, ultimately becomes 

 invisible. In time some of the leaves put forth branches. 

 The plant being thus produced by humidity from the seed is 

 still soft and moist. Growing actively both above and below ; 

 it cannot as yet bear fruit, for it has not the quality of force 

 and reserve (oura/jus Icr^vp-i] KCU mapa) from w r hich a seed 

 can be precipitated. But when, with time, the plant becomes 

 firmer and better rooted, it develops veins as passages both 



iraidiov, On the nature of the embryo, 29. 



