800 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
irritated and angry. Even the micro-organisms are subject to 
similar changes ; for instance, before thunderstorms in late fall, 
the wine fermentation can reach so great a violence as to cause 
the fermenting juice to suddenly run out of the vats. The 
greater the change in the atmosphere, the greater the unrest 
of the living being." If one happens to be at a farmhouse in 
our own country, where ice is not freely used, and a thunder- 
storm occurs, any farmer's wife will complain that the thunder 
and lightning have soured the milk. Continuing, Professor Sajó 
calls particular attention to the “great unrest and activity that 
takes place in the insect world just in the sultry hours pre- 
ceding a thunderstorm, and to the fact that insects in the air 
at the time the storm bursts are driven like chaff to great 
distances, — perhaps into other countries, across rivers, lakes, 
and mountains; not only the species that fly but many that 
do not fly may thus be transported to new homes." An 
again, * Many Aphides creep to the crowns of the plants, then 
drop themselves at the proper moment into the violent current 
of the storm. A number of these insects land in places where 
there is no food supply for them and they die. A part of them 
reach places where their species is already established, and 
fare no better. Part are thrown into the water, sometimes 
in oceans, and perish. A proportionally small number arrive 
at such places as may be called really favorable for their diffu- 
sion, vzz., where the species has never established itself before, 
or, having done so, died out before the arrival of newcomers, 
and, therefore, natural enemies had not preceded them. Such 
individuals as are thus thrown into favorable places have a 
chance to multiply into large, populous colonies within a short 
space of time, and continue until their enemies find them out, 
or they become over-populous and devour all of their food 
supply, resulting in what to them is famine.” 
- There is probably not an American entomologist who 
has not encountered illustrations similar to those enumerated 
by the writer of the above, and, while we may not have 
wholesale introductions of new things among us, there is 
no doubt that localities are often first colonized by certain 
kinds of insects in this manner, whereas the wind or the 

