U. S. DEPARTMENT OF AGRICULTURE 
BIOLOGICAL SURVEY 
WASHINGTON, D. C. 
December 18 1896m 
Mr. William Brewster, 
Cambridge, Mass. 
Dear Brewster: 
Your letter dated December 15 has this moment arrived. 
In the case of Canon 33 have you not agreed to an interpreta¬ 
tion which you and Faxon think will necessitate the smallest number 
of changes, rather than with the only interpretation which the plas¬ 
ticity of the English language permits one to draw from the Canon it¬ 
self? Coues stated at the meeting here that he dr.ew up this Canon 
himself, and drew it up with special reference to the two distinct 
classes of cases which it covers. You certainly must admit that two 
classes of cases are distinctly provided for, while your ruling seems 
to fall under the second class only. By what distortion of the Eng¬ 
lish language can you understand the first clause to mean anything 
different from what it says, namely,that "a specific or subspecific 
name is to be changed when it has been applied to some other species 
of the same genus”. You and Allen both admit that Picus mo ntanu s, 
belongs to the same genus as Dr yobates montanus, although it was not 
described under the same generic name; therefore, it distinctly falls 
under the first clause, but does not come under the second, which 
provides for cases used previously in combination with the same gen- 
