-I s - THE AMERICAN BISONS. 



Explanation of Table X. 



1. Bison americanus. A vm- old male from Kansas (M. ('. '/.., No. 95). 



2. Bison americanus. Male, ten to twelve years old, from Kansas (M. C. Z., Xo. 91). 



3. Bison americanus. Very old male, from Kansas. 



4. Bison americanus. Very old male, from Kansas (M. C. Z., Xo. 93). 



5. Bison americanus. Male, a! t fifteen years old, from Kansas (M. C. Z., Xo. 10). 



6. Bison americanus. Male, about six years old, from Kansas (M. C. Z., Xo. 11). 



7. Bison americanus. Male, about four years old, from Kansas (M. C. Z.. Xo. 94). 



8. Bison americanus. Male, about ten years old, from Kansas (M. ('. Z.. Xo. 97). 



9. Bison americanus. Male, about twelve years old, from Kansas (M. ('. Z.. Xo. 99). 



10. Bison mi" ricanUS. Male, four or five years old, from Kansas (M. C. Z., Xo. 100). 



11. Bison americanus. Male, about six \ ears old. from Kansas (M. C. Z.. Xo. 102). 



12. Bison americanus. Male, about twelve years old, from Kansas (M. C. Z.. Xo. 1770). 



13. Bison americanus. Male, about twelve years old, from Kansas (M. C. Z., Xo. 1771). 



14. Bison americanus. Mali-, about twelve years old, from Kansas (M. C. Z, Xo. 1215). 



15. Bison americanus. Male, aliout fifteen years old, from Kansas (M. (.'. Z., Xo. 121 G). 



16. Bison americanus, Male, ten or twelve years old, from Kansas (National Mus.. Xo. 12.233). 



17. Bison americanus. Female, four or five years old. from Kansas (M. C. Z., Xo. 1937). 



18. Bison americanus. Female, about three years old, from Kansas (M. ('. Z., Xo. 17C8). 



19. Bison americanus. Female, about three years old, from Kansas (M. C. Z.. Xo. 96). 



20. Bison americanus. Female, about nine years old. from Kansas (M. ('. Z., Xo. 101). 



21. I'.isnn americanus. Female, about >i\ years old, from Kansas (M. ('. Z., X*o. 105). 



22. Bison americanus. Female, about *ix year- old, from Kansas (M. ('. '/... Xo. 92). 



23. Bison bonasus. Female, about five or >i\ years old (M. C. '/... Xo. 1790). 



24. Bison bonasus. Old male, from Menagerie of Schoenbrunn (M. C. Z , Xo. 165). 



25. Bison bonasus. Male. Measurements a- given by Richardson, in Zool. Voy. of the Herald, p. 122. 



26. Bison bonasus. Old male, from Shoenbrunn. Measurements as given by Cnvier (Ossem. Fo-.., Sd 



ed., Tome IV, p. 121) 



27. Bison oonasiis. Male, about >i\ years old. from the Vienna Museum (National Mus., Xo. 11,51 1). 



Individual Variation. — The American bison presents a considerable range 

 ofwhal may he termed individual variation. This lias already been noticed 

 in respect to the metacarpal hones (see Table VIII and Plate X). where it 

 was shown thai not always the thickest andstoutesl examples are the longest. 

 Thus a metacarpal of a male 1 92 nun. in length exceeds in all other dimensions 

 another specimen having a length of 213 mm. A similar difference is trace- 

 able thrOUghoul the skeleton (see Table 1 X ). so that we have individuals 



that presenl in all parts of their structure a Blender or attenuated form, and 

 others that are relatively thick and -tout, the t . 1 1 ! . ■ - 1 and longest specimens 

 being sometimes exceeded in Btoutness, comparing hone with hone, by 

 those of considerably less stature. There are again individuals that differ 

 from the average in general bulk, without presenting any other unusual 

 differences. Variations in the relative length of the different bones of the 



