19, 1 Light: Notes on Philippine Termites, II 25 
the subgenera to generic rank wherever possible. Such a change 
seems to me to be conducive to clearness and usableness, par- 
ticularly in the older genera, Kalotermes, Eutermes, and Termes, 
and I shall adopt it in my work on the Philippine termites. 
With the above changes Holmgren’s arrangement of families 
and genera is an admirable one, and I shall follow it. It may 
be of interest to point out here that in addition to the characters 
already pointed out by Holmgren as separating the three higher 
families it is very significant that the protozoan faune of the 
guts of the three groups are characteristic. I find none of 
the polyflagellate protozoa (Hypermastigina) in the gut of any 
of the Termitidz (Metatermitide of Holmgren), and those of the . 
Rhinotermitide (Mesotermitide of Holmgren), while very simi- 
lar in all the genera of that family, are quite different from those 
found in the Kalotermitide (Protermitide of Holmgren). This 
is significant in connection with the position which Banks 1 gives 
to Leucotermes in his classification. 
MEASUREMENTS AND TERMS 
While measurements made from a small range of specimens 
must not be considered as fixing the variational range for a 
species and must be used with caution, such measurements are 
of undoubted value in the determination of species in a group 
where specific lines are by no means easy to draw, and I shall 
as a rule accompany my descriptions by a set of such measure- 
ments, 
There has been a considerable degree of carelessness on the part 
of some workers in furnishing the details necessary for an 
intelligent use of specific descriptions. Measurements are given 
for body length, head length, head length without mandibles, 
pronotum length, etc., without making it clear just what such 
measurements mean. If systematic work is to accomplish any- 
thing worth while the forms of animals should be so described 
that they may be recognized by other investigators—not only the 
specialist in the group, but the biologist interested in the study 
of animals from other points of view, or even the layman 
desirous of knowing the common forms of life about him. But 
far too many systematic descriptions seem to be written for the 
specialist only, and they are often of little value to him in the 
absence of type material. May I go further and speak from 
the experience gained in entering a new systematic field? The 
needless use of terms of limited application should be avoided. 
* Banks, N., and Synder, T. E., Bull. U. S. Nat. Mus. 108 (1920) 75. 
