Our experiments on hearing met with negative results. The wasps seemed insensible to any noise we could make or that we could produce by whistles of various degrees of shrillness. This of course does not show that they cannot hear, and any one who has been unfortunate enough to disturb them in the neighborhood of their nest will remember how their angry buzzing seemed to serve as a battle cry to gather all the members of the clan for the attack. Our Vespas began to work an hour or two after sunrise, and did not stop until dusk. One cloudy evening when darkness fell early they continued to return to the nest, being able to fly to the right spot without any hesitation, although our vision did not permit us to see the opening without going down on our knees and looking closely. At last it grew perfectly dark, and we stuffed a handkerchief into the hole, with the result that seventy–five, coming home without a ray of light to guide them, were shut out, and were found clustered about the spot on the following morning. We wanted to estimate the amount of labor done by a worker in a day, and so, rising one morning at the first bird call, we went out into the freshness of dawn, and for an hour had the world to ourselves; but a little before five a few straggling wasps that had stayed out all night began to bring in loads, and by half past seven they were fairly under way. From half past four until twelve we counted all that passed, 4534 going out and 3362 coming home; and with all this activity there seemed to be no pleasure excursions, for each one carried food when returning, and took out a pellet of earth when leaving. We once raised a little garden from the pellets that were dropped on our porch table where we kept a bowl of water. Wasps are great drinkers, and when they find such a provision they come frequently to refresh themselves, dropping their loads as they alight. This habit of holding on to their loads until they settle down may perhaps make them a factor in extending the boundaries of plant distribution, both under ordinary conditions and when, as must often happen with little creatures flying so high, they are blown to long distances from home. [Illustration: PAPER NEST WITH SIDE REMOVED TO SHOW CONSTRUCTION OF COMBS]