DESCRIPTION OF PLATES. 



Plate 1. 



Fig. 1. Pure wild Cavia rufescens c? 33. 



2. i wild hybrid (C. fyfeteem cf XC poreeMiM 9)9. 



3. I wild hybrid (J wild hybrid 9 XC. ru/escens cT) 9 . 



Plate 2. 



Fig. 4. Mid-dorsal hairs of \ 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 darkw. 



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



tame is as in fig. 4. 



6. Mid-dorsal hairs of (^804 (^ 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 cf 804. Compare fig. 6. 



8. c?804, sV ''<^ld 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. cfl, the original wild male ancestor of all wild and hybrid animals in these 

 experiments. 



11. cfSB, male guinea-pig. 



12. cf 10, I wild hybrid. 



13. cflSl, J wild hybrid. 



14. 0^206, 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 otherwise 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, J wild hybrid. 



18. 987, i wild hybrid. 



19. 9264, i wild hybrid. 



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

 a wild male, a \ wild male, and a i wild female skull. 

 Fig. 20. cf 1, the original wild male ancestor of all wild and hybrid animals in these 

 experiments. 



21. c3'24, pure wild eon of cfl. 



22. cf 78, J wild hybrid. 



23. cf 111, J wild hybrid. 



24. cf 169, 1 wild hybrid. 



25. cf 617, male guinearpig. 



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



experiments. 



27. 922, J wild hybrid. 



28. 996, i wild hybrid. 



29. 9 171, I wild hybrid. 



30. 9 30, female guinea-pig. 



31. cf24, pure wild son of cf 1. 



32. cf 23, largest i wild male. 



33. 9 119, J wild female. 



133 



