Figure 18. Table of illustrations from Tredern's DISSERTATIO 

 . . . OVI AVIUM HISTQRIAE ET INCUBATIONIS 

 PRODROMUM. , 



Key: 



Fig. 1. Internal parts of domestic hen: 1- aorta; 



2- mesenteric vessels; 3- large intestine; 4- rectum; 



5- cloaca; 6- caecum; 7- fat; 8- yolk of the egg in the 

 ovary; 9- groove; 10- vessels of the yolk membrane; 



11- attachments of round ligament; 12- infundibulum; 



13- curvature of the uterus; 14- cervix of uterus; 



15- peritoneal ligament of the uterus; 16- stretched uterine 



ligament; 17- anal opening; 18 and 19- its external and 



internal pulp; 20- feathers; 21- faeces; 22- villous membrane 



of the intestines; 23- bowl; 



Fig. 2. egg, opened under water: 1- shell; 2- second white; 



3- third white; 4- chalaza; 5- yolk; 6- belt of yolk membrane; 

 7- corrugations of yolk membranes; 8- cervic of white ligament; 

 9- stretched white ligament; 10- transparent part of the 

 ligament; 11- second proper ligament of the egg; 12- first 

 proper ligament of the egg; 13- groove; 



Fig. 3. view of the embryo from the front. Third hour of the 

 4th day of incubation: 1- brain; 2- eye; 3- forehead; 



4- rudiment of the upper jaw; 5- opening of the beak; 



6- upper jaw; 7- heart; 8- vertebrates; 9- wing; 10- legs; 

 11- tail; 12- chorion; 13- yolk duct; 14- vascular zone; 



Fig. 4. 6th day of incubation: 1- forehead; 2- eye; 3- opening 

 of the beak; 4- dorsum of the beak; 5- its lateral parts; 

 6- basis of the upper parts of the beak; 7- fissures of the 

 future nostrils; 8- upper jaw; 9- trachea; 



Fig. 5. 8th day of incubation: 1- beak dorsum; 2- nostrils; 



3- basis of upper jaw; 4- lower jaw; 5- beak opening; 



Fig. 6. twelfth hour of the 9th day: 1- nostrils; 2- node 



on beak dorsum; 3- lateral parts of the upper jaw; 4- opening 



of the beak; 5- lower jaw; 



Fig. 7. 1- forehead; 2- nostrils; 3- node of the beak; 



4- lateral parts of the beak; 5- lower jaw; 6- trachea, 

 visible through tectum; 



218 



