446 



JAS. P. HILL. 



Skin and 

 skeleton 



P. nasula, Stage C. 



7 mm. 

 from crown to rump. 



P. obesula, Stage D. 



875 mm. 

 from crown to rump. 



Skeleton in the me- Nucleated epitrichial 

 seuehymatous stage.; layer on epidermis. 

 No trace of hair, 

 claw aniagen on 3rd 

 and 4th fore digits. 

 Skeleton cartilagi- 

 nous. 



P. nasuta, new-born. 



Stage E. 



14 mm. crown to rump. 



Head length 6 mm. 



Thick epitrichial layer 

 on epidermis. Well- 

 marked hairanlagen 

 on snout and cheeks. 

 No ossification in 

 cartilaginous skele- 

 ton, which is now 

 fully formed. Up- 

 per and lower jaw 

 ossifications. 



Comparing the above three embryos with the tables and figures in Keibel's 

 'Normentafel zur Entwickelungsgeschichte des Schweines (Sus scrofa 

 domesticus),' Jena, 1897, they correspond, as nearly as one can judge, as 

 follows : 



Embryo C to No. 85, Fig. 24. 

 Embryo D barely to No. 91, Fig. 28. 

 Embryo E to No. 93. 



