35 



while the countr}?^ was yet unsettled by the white man, 

 states that a kind of worm had eaten off the blades of maize 

 and also of a tall white grass, so that the naked stems of 

 both stood "four foot high." From similar data, gathered 

 from different sources, relative to this point, it seems that 

 this irregular incre^ise and decrease of some species, in point 

 of numbers, has prevailed since long prior to the advent of 

 the Caucasian, and though it may have been affected by the 

 advance of civiHzation, this influence has not been of a vital 

 importance. 



When we come to take up the second factor in this prob- 

 lem, we find everywhere manifestations of the most radical 

 disarrangement of natural conditions. Entomologists are 

 everywhere familiar with the fact that many species of m- 

 sects are very abundant in certain limited areas, while out- 

 side of these they are often very rare. Many of us remem^ 

 ber very well when the large Tiger Beetle, Amblychila 

 cyUndriJormis^ was exceedingl}'^ rare, and it so continued 

 to be until their habitat in Kansas was discovered, when 

 they were captured by the hundreds. On settling in a new 

 locality, the first move an insect collector makes is to score 

 the country about in search of what he terms "collecting 

 grounds," which may comprise only a tract a few yards 

 square — a little glade, or a small grove, a thicket or a bit of 

 overgrown swamp — invariably more or less low lying and 

 near water. The higher and dryer places are less prolific 

 in insect life. If our collector remains in the same locality 

 for a series of years, he will soon be able to determine just 

 where to find certain species at a certain time of the year, 

 and possibly on certain days. A friend of mine in Illinois 

 tells me that he always finds certain species of Catocala, in 

 a small bit of woodland, at a certain tinse of the year when 

 certain temperature prevails, and a light wind is blowing 

 from a certain direction, and outside of this little isolated 

 wood, and under other conditions he is able to get almost 



