120 AGE, GROWTH, AND DEATH 



recognisable parts and several times the volume it had 

 when one day old. The next figures, Nos. 4 and 5, 

 illustrate the alteration which occurs during, approx- 

 imately, the third day. It is obvious that the embryo 

 has again made an enormous increase in volume. 

 The eye has developed, the heart has become large, 

 the tail is projecting, the dorsal curve of the future 

 neck is distinguishable. We pass next to the fourth 

 day, No. 6. Is it not a strange looking beast, with 

 its wing here and leg there, a little tail at this point ; 

 an enormous eye, almost monstrous in proportion ; 

 and, finally, here a great bulge caused by the middle 

 division of the brain. After five days, Nos. 7 and 8, 

 we have a chick the brain of which is swelling, causing 

 the head to be of so queer a shape that, with the 

 eye which seems out of all proportion to the rest of 

 the body, it imparts an uncanny look to the embryo. 

 The wing is shaping itself somewhat, and the ends of 

 the leg, we can see, will, by expansion, form a foot. 

 Finally, the chick after seven, No. 9, and after eight 

 days, No. 10, is figured. In the short interval of only 

 six days the chick grows from the size represented by 

 No. 2 to that shown in the last figure upon the plate. 

 It is an enormous increase. Suppose a chick after it 

 was born were to grow at such a rate as that ! The 

 eight-day embryo is perhaps thirty or forty times as 

 big as it was six days before. It would seem marvel- 

 lous to us if a chick after it was hatched should become 

 in six days thirty times as large and heavy as when 

 it first came out from the egg. It is perhaps advis- 



