DESCRIPTION OF PLATES. 



Plate 1. 

 Fig. 



1. Pure wild Cavia rufescens cT' 33. 



2. 5 wild hybrid (C. rufescens cfXC. porcellus 9)9. 



3. f wild hybrid (§ wild hybrid 9 XC. rufescens cf) 9. 



Plate 2. 



Fig. 



4. Mid-dorsal hairs of I wild hybrid. The agouti was received from the wild 



and is about the same shade as in the tame. In some cases the pure wild 

 agouti was a trifle darker. 



5. Mid-ventral hairs of | wild hybrid. Its relation to the pure wild and pure 



tame is as in fig. 4. 



6. Mid-dorsal hairs of cf804 (i^ wild hybrid), a typically modified, darkened 



agouti. The agouti was received from a pure wild strain. The ticking 

 is very slight. 



7. Mid-ventral hairs of d'SOi. Compare fig. 6. 



8. cf 804, ,^4^ wild hybrid. Compare figs. 6 and 7. 



9. Ventral view. The same animal. 



Plate 3. Photographs of male skulls in parent species and hybrids. 



Fig. 10. d'l, the original wild male ancestor of all wild and hybrid animals in these 

 experiments. 



11. 6^86, male guinea-pig. 



12. d'lO, § wild hybrid. 



13. cf 151, i wild hybrid. 



14. d'206, i wild hybrid. 



Note. — These and all other reproductions of skulls and bones are natural size, and as 

 near the calculated averages as possible, unless otherv/ise stated. 



Plate 4. Photographs of female skulls in parent species and hybrids. 



Fig. 15. 9 3, the original wild female ancestor of all wild and hybrid animals in these 

 experiments. 



16. 9 12656. female guinea-pig. 



17. 9 63, ^ wild hybrid. 



18. 9 87, i wild hybrid. 



19. 9 "264, i wild hybrid. 



Plate 5. Photographs of lower jaw-bone in parent species and hybrids. Photographs of 

 a wild male, a 5 wild male, and a J wild female skull. 

 Fig. 20. c?l, the original wild male ancestor of all wild and hybrid animals in these 

 experiments. 



21. cf 24, pure wild son of cf 1. 



22. cf 78, h wild hybrid. 



23. d^lU, i wild hybrid. 



24. cfl69, I wild hybrid. 



25. cf617, male guinea-pig. 



26. 9 3, the original wild female ancestor of all wild and hybrid animals in these 



experiments. 



27. 9 22, i wild hybrid. 



28. 9 96, I wild hybrid. 



29. 9171, i wild hybrid. 



30. 9 30, female guinea-pig. 



31. cf24, pure wild son of cfl- 



32. cf 23, largest ^ wild male. 



33. 9119. i wild female. 



133 



