380 Annals Entomological Society of America [Vol. VIII, 
If this principle is accepted, as most naturalists do, the 
necessity of making quantitative valuations to the amount of 
variation separating groups is necessary. The traditional 
primary classification of insects is represented by the common 
names and was adapted by Linnaeus for his orders. In these 
the quality of variation is represented by the differences between 
bees, flies, butterflies and beetles. The practical question to 
be settled is whether the difference between, say an ant lion 
and a sialid, is'of the same order of magnitude. It would seem 
that those who have gone to the extreme in increasing the 
number of orders have either ignored or rejected this principle. 
After wings were produced we must conceive that there was a 
single order, family, genus and species, that first there occurred 
a multiplication of species, some of which became more, and, 
finally, were generically different, and last of all the difference 
of the most remote forms represented different orders. The 
differences between the Orthoptera and Neuroptera most 
probably represents the progressive development of a whole 
family, rather than a great mutation of a single species and that 
historically there was a period where two families representing 
the two orders were families of the same order. A time is 
reached when the differences become great enough to be of 
ordinal value. 
We must strive toward the goal where we can assign a 
quantitative degree of differentiation as representing family 
rank and another for order rank, etc. to replace our present 
plan of making such groups on the basis of indefinite mental 
impressions. 
DISTRIBUTION. 
Most collectors of insects are very careful to have the 
locality and date with every specimen appreciating that the 
geographical and seasonal distribution of insects are questions 
of great importance. The data accumulated in this way is 
of very unequal value, because in some cases the absence of 
record indicates the absence of the species from a locality and 
in other cases may indicate the rarity of the insect. The 
biologic significance of an insect depends on its degree of 
abundance. The real importance of the subject will lie in 
accumulating data to show the part each species plays. 
