POULTRY LABORATOEY GUIDE 45 



marked out rather than by the formation of new 

 ones. On the fourth day the wing fold appears 

 midway on the curvature of the body, and the 

 folds forming the hind limbs also appear, being 

 shorter than the front Umbs. The embryo in- 

 creases greatly in size. 



Make a sketch of the six-day-old embryo, show- 

 ing the organs above named. Take notes on the 

 differences seen in the various-aged embryos, 

 briefly describing changes as seen. 



EXERCISE XIII 



Development op the Chick from the Eighth 

 TO THE Nineteenth Day 



Take from the incubator or from under the 

 hen eggs whose embryos are eight, twelve, sixteen, 

 and nineteen days old respectively, and test to see 

 if they are normal. Carefully break the shell and 

 place contents in shallow dish, using great care 

 not to break the yolk. Examine carefully with 

 the naked eye the development which the em- 

 bryo makes from day to day. 



From the seventh day on, the business of the 

 chick (for such it may now be called) is to grow, 

 and it is only necessary to notice a few of the 

 more important changes which take place bring- 



