1908 ] 
Proceedings of N. C. Academy of Science 
49 
2. The Alleghanian Zone , includes practically all between the 
elevation of 2,500 ft. and 4,500 ft. This includes most of the 
Blue Ridge and Smoky Mountains, Nantahala Mountains, Bal- 
sam, Pisgah Ridge and the lower elevations of Black Mountains 
and others mentioned as belonging to the Canadian zone. 
3. The Upper Austral Zone includes all of the state north and west 
of a line drawn from Suffolk, Va. to Raleigh, thence to Charlotte, 
thence to the South Carolina line near Tryon in Polk County — 
except that portion already assigned to the Canadian and Alle- 
ghanian zones. 
4. The Lower Austral Zone includes all of the state to the 
south and east of the line just mentioned. 
Lists are given of the characteristic animals in each of these 
zones, and mention is made of a number of exceptional records, 
where animals have been taken beyond the limits of what their 
range would supposedly be. 
The counties in the extreme northwest part of the state have 
not yet been zoologically explored, and are therefore not yet 
assigned to any zone, awaiting the accumulation of more records. 
The Relation of Bovine Tuberculosis to the Public Health. Tait 
Butler of the Dept, of Agriculture, Raleigh. 
“The Twenty -Seven Lines Upon a Cubic Surface .” Archibald Hen- 
derson of the University of North Carolina. 
In his paper, Dr. Henderson explained that by the selection of 
a highly symmetrical equation of a cubic surface : 
by a proper choice of constants x It y zi z x , w x ; x 2 , y 2 , z 2 , w 2 ; and 
finally by employing a regular tetrahedron of reference, that it 
was not difficult to derive very simple and symmetrical equations 
of the twenty-seven lines upon the cubic surface, and therefore to 
