THE EMBRYOLOGY OF THE OPOSSUM 



97 



Fig. 32 Photographs of wax models of pharynx of early and late specimens 

 of stage 27. A, early specimen (17154) showing lung pouches at dorsolateral 

 corners of pharynx. B, late specimen (17142) showing lung pouches at ventro- 

 lateral corners of pharynx. 



Fig. 33 Lateral reconstructions of the pharynx from stage 25 through stage 29 

 to show the development of the branchial pouches and lungs. 



