50 THE CHINCH BUG. 
the massing appeared to be an essential requisite. Whether this was 
sufficient of itself, or whether the effect of massing was to reduce the 
vitality of the individual bug, and thus render it more susceptible to 
the spores of the fungus, it is impossible for me to decide; but I have 
long suspected that the latter was the true solution of the problem. 
We know that most domestic animals or fowls thrive best and are 
the most vigorous when kept in small flocks, while among humans the 
maximum of health and minimum of disease is obtained where 
the individuals are scattered over a moderate area per capita and the 
atmosphere is dry and pure; low, damp, and ill- ventilated quarters, 
when overcrowded, being especially fatal, particularly to the young. The 
individual in perfect health and vigor may be said to be above and out 
of reach of disease, and before the two can be brought together there 
must be some interacting element that will bring the individual down 
to a point where it can be reached by the disease; that is, the disease 
can rise only to a certain plane and the victim must be first attacked 
by some element not necessarily fatal in itself, but sufficiently depres- 
sing to bring the individual down to where it can be grasped by the 
disease. 
Meteorological influences favoring development of fungous enemies of 
chinch bug. — When human beings are overcrowded and some disease 
like yellow fever is introduced among them, every one knows the effect 
of a low, damp locality under a high temperature and with both air 
and water more or less stagnaut. Even the once healthy and vigorous 
are more or less reduced and enervated by their environment, and thus 
brought within the influence of the deadly disease. Again, if an indi- 
vidual is stricken and forsakes his miasmatic surroundings for those 
more salubrious, the disease may still overcome him, but seldom spreads 
to others, except such as come in actual contact with either himself or 
his belongings, while if not too much reduced before changing his 
habitation the chances are much more favorable for his recovery. 
It seems to me that in this matter of meteorological conditions and 
their relation to the effect of entomogenous fungi ou the chinch bug 
we are really dealing with the same problem in a different field. The 
young chinch bug, which has not yet come into possession of its full 
measure of strength, and the spent females, which have lost theirs, fall 
easiest as the prey to these fungi, while the fully developed bugs, 
endowed with health and vigor, appear to be to some extent immune 
to the attacks of these enemies, and if not massed in large bodies they 
seem still more likely to escape destruction. In the timothy meadows of 
northeastern Ohio I have found an occasional dead adult in late autumn, 
but the fungus had certainly not claimed many victims, though both 
the long and the short winged forms were present in considerable abun- 
dance, clustered about the roots of grass. With Forbes I believe that 
after becoming fully matured the chinch bug is, largely at least, beyond 
the reach of Sporotrichium. What is the element that serves to ener- 
