EDWARD S. MORSE ON 



ADULT SALAMANDER AND EMBRYO BIEDS. 



Fig. l. 

 Salamander. 



Fig. 2. 

 Tern. 



Fig. 3. 

 Sea Pidgeon. 



Fig. 4. 

 Blue Heron. 



Fig. 1. Fore leg of Salamandra maculosa, showing the intermedium, i, in its position 

 between the distal ends of the tibia and fibula. 



Fig. 2. Portion of leg of common Tern from an embryo, showing the appearance of 

 the intermedium between the distal ends of the tibia and fibula. 



Fig. 3. Portion of leg of the Sea Pigeon from an embryo with the intermedium in 

 front of the tibia, from the widening of the tibia so as to compass in width the tarsal 

 bones. 



Fig. 4. Distal extremity of the tibia of the Blue Heron from an advanced embryo. 

 In this figure only the intermedium is shown. Its distal end had not yet coossified with 

 the other tarsal bones. 



YOUNG BIRDS. 



Fig. 5. 



Fig. 6. 



Fig. 7. 



Fig. 8. 



Fig. 9. 

 Young Blue Heron. 



Young Ostrich. Young Fowl. 



Figs. 5 and 6. Front and side views of the distal end of the tibia and tarsus of a 

 young ostrich. From a figure of Professor Huxley's in Quarterly Journ. Geological Soc., 

 above referred to. These figures show the tarsal bones including the intermedium 

 ankylosed together ; the intermedium appearing as an ascending spur or process of the 

 other tarsal bones. 



Figs. 7 and 8. Front and side views of the distal end of tibia and tarsus of a young 

 fowl, from Huxley's Anatomy of Vertebrated Animals, p. 253, fig. 88. The condition 

 and general appearance are the same as in the figures of the young ostrich. 



