444 THE AMERICAN NATURALIST. [Vov. XXXII. 
The second half of the paper is devoted to a research on bees, 
Do bees of one hive recognize one another ? 
Bethe finds that they, like ants, do not know individuals either by 
sight or smell, but that, ad-ovo, they react in a friendly manner toward 
their own colony “nest material,” and in an unfriendly manner 
toward a “ nest material ” of bees of other hives. As with ants, two 
“nest materials ” may be so mixed as to become one, as is shown by 
the method necessary in introducing a new queen into a queenless 
colony. If unprotected she is at once killed. If, however, she is put 
among them for a few days, protected by a gauze box, and then 
liberated, she is received. At first her “nest material” calls out the 
fighting reflex of the hive, but given time the “nest materials” of 
both mix and cease to afford any adverse stimulus. That the differ- 
ence in the “nest materials” of two hives is produced by congenital 
diversity is shown by the following 
A hive was divided, half the grubs of the old being given to the 
new hive. In a few days, when these young bees had come out, 
some were taken from the old hive to the new, and were treated as 
belonging to the new hive. For two or three weeks bees of one hive 
could be placed in the other and be well received, but after this time 
the brood of the new queen began to come out. One of these new 
bees introduced into the old hive would be killed, and bees from the 
old hive would be attacked by the new brood of the new hive. Old 
bees of the new hive if isolated twenty-four hours were still received 
by the old hive, but after three weeks longer no more mixing of the 
two hives could be effected. The “nest material” from the new queen 
had become strong enough to modify that of m whole hive. 
How do bees find their way? 
They could not leave a material in the air, as is left by ants on 
their paths, which could guide them to and from the hive, but since 
a male moth has been known to locate a female several miles distant, 
it seemed possible that still a volatile chemical material might be the 
agent which guides bees. A tunnel of paper placed over the entrance 
to the hive caused a great change in the actions of the bees; few 
crossed over the paper either in or out, but collected at the edge, 
both on the inside and outside of thé tunnel, and buzzed. When it 
was removed there was a gush of bees, both entering and leaving the 
hive. A bridge of paper over the entrance caused no such disturb- 
ance, since the entrance board was left free, on which there was a 
material which guided the crawling bees. 
If fying bees are guided by the “ nest material ”? which is radiating 
