like projections; upper and lower mandibles pres- 

 ent; auditory opening readily discernible; pipping 

 tooth barely discernible. 



10 Days: Midbrain appearing as moderate protuberance; 



prominent blood vessel visible along side of 

 neck from base of skull to base of anterior ap- 

 pendages; toes partially separated; heart beat no 

 longer visible; feather papillae evident on head, 

 spinal tract, and thighs. 



11 Days: Toes completely separated; feather papillae 



discernible in all feather tracts; midbrain appear- 

 ing as only a slight protuberance; nostrils readily 

 discernible. 



12 Days: Feathering (darkly pigmented) appearing along 



spinal tract and about tail; development of pha- 

 langes evident. 



13 Days: Embryo appearing on its left side, bill touch- 



ing abdomen, feet near head; eyelids commencing 

 to close, apertures assuming an oval shape; 

 feathering appearing on thighs and elbows; blood 

 vessel along side of neck still apparent. 



14 Days: Feathering appearing on anterior edges of 



auditory openings and on top of head and upper 

 margins of eye; scales on legs and feet barely 

 discernible. 



15 Days: Lateral view shown in figure; shell and yolk 



sac removed. Natural position of embryo as seen 

 in decapped egg: the long axis of embryo lying 

 parallel to long axis of egg, with head lying near 

 the large end of the egg (prior to this time, the 

 long axis of the embryo at right angles to the 

 long axis of the egg). Feathering continuous dor- 

 sally from base of beak to tail; scales on legs 

 and feet readily discernible; spur papillae evi- 

 dent. 



16 Days: Lateral view shown in figure; shell and yolk 



sac removed. Narrow semicircular bands of feath- 

 ers extending lateroventrally from the anterior 

 border of auditory openings to base of lower man- 

 dible; feathers present about eyes but not well 



developed; apertures of eyes assuming propor- 

 tions near normal for newly hatched chick. 



17 Days: Lateral view shown in figure; shell and yolk 



sac removed. Embryo almost entirely covered by 

 dovyn feathers, except on dorsolateral aspects of 

 head. 



18 Days: Lateral view shown in figure; shell and yolk 



sac removed. Feathering well advanced; eyelids 

 closed; eyes now appearing normal in relation to 

 head of chick; development of webbing between 

 toes evident. 



19 Days: Lateral view shown in figure; shell removed. 



Natural position of embryo as seen in decapped 

 egg: head lying on its left side with right ear and 

 eye in view; beak partially concealed by yolk 

 sac; right foot touching top of head, and left foot 

 touching lateral aspect of head; right wing start- 

 ing to pass over head; head commencing to rotate 

 to the right. 



20 Days: Natural position of embryo as seen in decap- 



ped egg: head continuing to rotate to the right, 

 with right wing shifting over head. Feathering 

 of embryo nearly complete; webbing of toes well 

 defined. 



21 Days: Lateral view shown in figure; shell removed. 



Natural position of embryo as seen in decapped 

 egg: embryo arched into pipping position; head 

 nearly covered by right wing (natural position of 

 wing shifted in photo to better show position of 

 head and beak); beak projecting from beneath 

 right wing, with pipping tooth lying in close prox- 

 imity to egg shell. 



22 Days: Lateral view shown in figure; shell removed. 



Natural position of embryo as seen in decapped 

 egg: position similar to that of 21-dav embrvo; 

 right wing covering head except for beak; beak 

 now in contact with egg shell; yolk sac nearly 

 absorbed. 



23 Days: Pipping of shell completed. Embryo emerges 



as hatched pheasant chick. 



LITERATURE CITED 



Dustman, E. H. 



1949. Nesting and production of the ring-necked pheasant in north-western Ohio following a population decline. Doctoral 

 thesis, Ohio State University, Columbus. 305 pp. 



Fant, R. J. 



1957. Criteria for aging pheasant embryos. Jour. Wildlife Mgt. 21(3):324-8. 

 Westerskov, Kaj 



1950. Methods for determining the age of game bird eggs. Jour. Wildlife Mgt. 14(l):56-67. 



