ideas. In support of this I may adduce the following experiment: Two strips of paper were attached to the board just mentioned (p. 54), and parallel to one another, and at the other end of each I placed a piece of glass. In the glass at the end of one tape I placed a considerable number (three to six hundred) of larvæ. In the second I put two or three larvæ only. I then took two ants, and placed one of them to the glass with many larvæ, the other to that with two or three. Each of them took a larva and carried it to the nest, returning for another, and so on. After each journey I put another larva in the glass with only two or three larvæ, to replace that which had been removed. Now, if other ants came under the above circumstances as a mere matter of accident, or accompanying one another by chance, or if they simply saw the larvæ which were being brought, and consequently concluded that they might themselves also find larvæ in the same place, then the numbers going to the two glasses ought to be approximately equal. In each case the number of journeys made by the ants would be nearly the same; consequently, if it were a matter of smell, the two routes would be in the same condition. It would be impossible for an ant, seeing another in the act of bringing a larva, to judge for itself whether there were few or many larvæ left behind. On the other hand, if the strangers were brought, then it would be curious to see whether more were brought to the glass with many larvæ than to that which only contained two or three. I should also mention that every stranger was imprisoned until the end of the experiment. I will select a few of the results:
Experiment 1.—Time occupied, one hour. The ant with few larvæ made six visits, and brought no friends. The one with many larvæ made seven, and brought eleven friends.
Experiment 3.—Time occupied, three hours. The ant with few larvæ made twenty-four journeys, and brought five friends. The one with many larvæ made thirty-eight journeys, and brought twenty-two friends.
Experiment 5.—Time occupied, one hour. The ant with few larvæ made ten journeys, and brought three friends. The other made five journeys, and brought sixteen friends.
Experiment 9.—Time occupied, one hour. The ant with few larvæ made eleven journeys, and brought one friend. The one with many larvæ made fifteen journeys, and brought thirteen friends.
Experiment 10.—I now reversed the glasses, the same two ants being under observation; but the ant which in the previous observation had few larvæ to carry off now consequently had many, and vice versa. Time occupied, two hours. The ant with few larvæ made twenty-one journeys, and brought one friend. The one with many larvæ made twenty-two journeys, and brought twenty friends. These two experiments are, I think, especially striking.
Taken as a whole, I found that in about fifty hours the ants which
