“ Splitters ” and “ Lumpers ” 
its appendages are black. The wings are bronzy-green. The 
insect inhabits Mexico and southern Arizona. 
“SPLITTERS” AND “LUMPERS” 
Every true naturalist is called upon to exercise the faculty of 
discrimination and the faculty of generalization. His work 
trains him to detect dissimilarities on the one hand and like¬ 
nesses on the other. His judgments as to likeness are expressed 
in the genera, the famiies, the orders, which he proposes. His 
judgment as to dissimilarities is most frequently expressed in his 
views as to species. When the two faculties of discrimination 
and generalization are well balanced and accompanied by the 
habit of patient observation, ideal conditions are reached, and 
the work of the naturalist in classification may be expected to 
stand the test of time. But where, as is often the case, one of 
these faculties is exalted at the expense of the other, there 
are certain to result perversions, which will inevitably cause 
trouble to other students. When a man cultivates the habit of 
discrimination to excess, he is apt to become, so far as his labors 
as a systematist are concerned, “a splitter.” A “splitter” 
magnifies the importance of trivial details; he regards minute 
differences with interest; he searches with more than micro¬ 
scopic zeal after the little things and leaves out of sight the lines 
of general resemblance. Huber, the celebrated naturalist, said 
that by patient observation he had come to be able to recognize 
the different ants in a hill, and, as one by one they emerged from 
their subterranean galleries, he knew them, as a man living upon 
a certain thoroughfare in a great city comes at last to know by 
sight the men and women who are in the habit of daily passing 
his windows. No doubt the critical eye can detect as great 
individual differences in the lower animal world as are to be 
detected among men. A student comes to apply himself with 
great zeal to searching out and describing these differences, and 
when he undertakes to say that because of them one form 
should be separated specifically from another he becomes “a 
splitter.” I recall an entomologist whose chief weapon of 
research was a big microscope. He would take a minute insect 
and study it until he was able to number the hairs upon its head. 
Then he would describe it, giving it a specific name. The next 
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