22 
Indiana University Studies 
in all the fields and woodlands and mountain forests thru 
which we journey at many miles an hour, for hour after hour, 
yesterday, today, and tomorrow. Nevertheless, our samples 
seem typical, for they are surprisingly uniform; and after 
such field experience, one comes to feel there is a reality 
summed up in the word “species” which is more than a few 
cabinet specimens or a bottle full of experimental material or 
a Latin binomial in a textbook. It is an existent, tremendous 
population of living individuals whose identities and dis- 
similarities, whose divergences from all other populations, 
whose origin in some remote past and extension thru actual 
generations and years of time, whose position on these par- 
ticular trees in these particular valleys and everywhere over 
these miles of actual country — it is this reality which, to us, 
constitutes the species problem. 
But we have met erinacei everywhere across the miles of 
Indiana and across Ohio. This morning we found it in the 
stream valleys and over the hillsides of West Virginia. At 
noon we still found it in more rugged country in the heart of 
the mountains, and now, near the end of the day, our road- 
signs read Maryland and we know we are near the crest of 
the Alleghanies. We get out of the car and climb the hillside. 
It is thick woodland and we find only stray galls now and 
again. They are smooth and naked specimens, for aught we 
can tell like the smooth galls of erinacei. A mile down the 
road we find an open meadow where two isolated trees offer 
promise of richer collections. The farm boy helps, and we 
collect more smooth galls while we wonder about the varied 
mixture which spreads so many miles back of us. It is 
drizzling now, and sheets of fine snow come whirling off the 
mountain, but we espy a tree in the next open, and in the 
gathering dusk find — many naked but only two spiny galls for 
our collections! We return to the car, wondering what is the 
matter with the sample. 
Before we sleep that night we shall have worked our way 
down into the valley of the Potomac. On the next day we 
shall collect across the valley of the Shenandoah, and in the 
days that follow out onto the sand coast of Virginia and south- 
ward along the shores of the Carolinas. Within a few months 
we shall breed the insects from the smooth galls we gather, 
and then we shall know that from the Maryland line to the 
