PROBABLE ORIGIN AND DIFFUSION. 67 
both broader and deeper, and it is not enough to simply tell the hus- 
bandman what an insect is and how to kill it. He must have some- 
thing along with that information to set his own mind to thinking, to 
work out problems or improve upon the solutions already given him, 
otherwise it is much like giving money to a professional beggar. If we 
can not give facts based upon demonstrations, then give the best expla- 
nation possible, even though it be a theory which is only expected to 
stand until some one does better. It is for the thoughtful, progressive 
farmer, as well as the student of geographical distribution, that this 
possible solution of the problem of the chinch bug has been prepared, 
and while the full practical value of the ideas advanced has yet to be 
demonstrated, this of itself can not be urged as sufficient grounds for 
not sending it forth for study and consideration. 
Thanks to the careful observations of Professor Sajo, on the Euro- 
pean species of chinch bug, Blissus dorice, it is now for the first time 
possible to compare the habits of this species with our own. 
INDICATIONS OF A PROBABLE DISTANT ORIGIN AND LATER DIFFUSION. 
In the United States our chinch bug, Blissus leucopterus, has a num- 
ber of peculiar characteristics, which, while having an economic inter- 
est, also points to a probable previous condition differing somewhat 
from the present, and not in all cases tending toward its present nu- 
merical strength. On the other hand, we find that it is now following 
some probably ancient habits which do not appear to be of any special 
benefit, but rather the reverse. 
In the first place, over its area of greatest destruction, it appears to 
prefer level tracts of country where the damp conditions consequent 
upon frequent rainfalls remain the longest, and in the second place, 
the period of spring ovipositiou is for the most part included within 
that during which the spring rains of the United States usually occur — 
that is to say, throughout the great grain belt, east of the Rocky 
Mountains, April and May are not normally months of severe drought, 
and it is during these two months that the larger portion of the eggs 
are deposited. As in the reverse of this, however, the period of fall 
ovipositiou, August and September, is far more likely to be favored by 
a lack of precipitation. These conditions do not always obtain, and it 
is because of the fluctuations that the insect is able to reach its maxi- 
mum in poiut of numbers. 
Another factor which plays quite an important part in reducing the 
number of adults maturing during unfavorable seasons may be found 
in the almost universally gregarious habits of the young, thereby ren- 
dering the ravages of the fungous disease the more universal ami fatal. 
In all of these peculiar characteristics as well as in some anatomical 
features, it seems to me we have a series of guide posts, so to speak, 
which indicate more or less clearly the ancient home of the species. 
and at least throw some light on i{s origin and d illusion. 
