220 Prof. 0. Heer on the House Ant of Madeira. 



possible. They do not go back to their nest, but hide themselves 

 in some cranny, or else under some near object ; but as soon as 

 the danger is over, they come out again, and betake themselves 

 afresh to their work. On such occasions one may satisfy oneself 

 that they do not see far. On taking away from an ant the 

 morsel it is carrying, it seeks about for it for some time, running 

 hastily in zigzags up and down; but at times stopping still, and 

 lifting its head up in the air. When placed at the distance of some 

 inches, the ant does not go straight up to it, as would be the 

 case if it could see it, but runs round about in diflfcrent direc- 

 tions, and only when at the distance of about an inch, springs 

 forward on it, as if seeming then to have first seen it. If we 

 examine the eye of this ant, we shall find that (as, however, 

 generally in all ants) it is of simple structure, as in most other 

 insects, and only consisting of a small number of lenses (Ocellen). 



In order to see whether these ants would try to pass over water, 

 I several times destroyed the connexion formed by the thread 

 between the vessel in the water and the wall, so that the ants 

 which happened to be in the vessel were quite cut ofi". If there 

 was a scum formed over the water (which is always the case 

 when the water has stood some time, a thin film spreading over 

 the water from the falling dust), then they tried to run away 

 over it ; a few got quite safe over, when the film could bear 

 them; but others broke through and were drowned. But I 

 never saw such a number fallen into the water that a bridge was 

 formed by the dead bodies, as is related of other sorts of ants, 

 and that by this means they reach vessels of provisions placed in 

 water. 



The work of these little creatures goes on alike day and night; 

 and if you look after them during the day, or in the night, or 

 early in the morning, you see always the same stirring activity. 

 Hence they seem to observe no fixed resting-times, at least none 

 in connexion with the change of day and night. This is also 

 the case with most of our own native ants, of which Pliny already 

 relates that they work by moonlight. These however hyber- 

 nate. The ants of warm countries, and so of Madeira, on the 

 contrary, do not. One of our own kinds [Formica fusca, L.) is 

 also found there, and it too continues the whole winter in activity. 

 Our house-ant is found throughout the whole year in nearly 

 equal abundance. The males and females probably appear at 

 the end of summer. Of the former I found only a single example, 

 whilst females were found in several nests till the new year. In 

 most cases it might well be that I observed none, because they 

 keep in the deeper parts of the nest. The females lay minute 

 little white eggs, out of which proceed little white maggots ; the 

 pupaj arc free, not enclosed in cases, as in our common ants 



