202 
27TH KEPOKT, BUREAU OF ANIMAL INDUiSTKY. 
prehistoric times. The differences between primigenius and trocho- 
ceros are essentially the same as those ^Yllich appear at the present 
time between the wild cattle of Chillingham Park and those of Lyme 
Park in England. In the latter case the change is regressive rather 
than progressive, as these cattle are presumably reverting to a wild 
condition from that of semidomestication. 
Bos FRONTOSUS. 
Bos fronton lis Nilsson is a fossil species found in Sweden. (See fig. 
14.) The contour of the skull is irregular, the forehead is broad, and 
Fig. 14. — Skull of Bos frontosiis. (From Rutimej-er.) 
the horns are situated on a short pedestal. The head is large in com- 
parison Avith the rest of the body. Nilsson thought it a distinct 
species having its original home in Germany, and the parent of the 
mountain cattle of Norway. Riitimeyer (1867) says the Scandi- 
navian remains are those of domesticated cattle. The broadening 
of the skidl is similar to that of the Naita cattle (Darwin) of South 
America, the Yorkshire swine, and the bulldog. H. von Nathusius 
says these changes are due to a reduction of muscular activit}^ which 
accompanies a change in the method of obtaining food. Riitimeyer 
says this does not explain the shortening and widening of the nasal 
bones. These changes, however, may be accounted for by the laws 
