152 Life and Immortality. 



strikingly characteristic of the Megachilidae, was evidence of 

 the most positive kind that Pelopaeus had nothing whatever 

 to do with their putting together. It bespoke a piece of 

 work that was entirely beyond the highest capability of her 

 being to execute. 



Each of the included leafy cells was one and one-eighth 

 inches in length, and just barely exceeding one-fourth in 

 width. Elliptical pieces of Spiraea, less in size than those 

 previously described, but arranged in a similar manner, com- 

 posed the several structures. Within each, a dead but per- 

 fectly-formed Megachile, encased in a cylindrical bag of silk, 

 was found, so that there could be no possible doubt of the 

 builder. That this inner fabric was the labor of some 

 mother Megachile admits not of a scruple, for no other bee 

 is known to construct a nest of like character. But what of 

 the outer enveloping fabric of mud ? It was clearly impos- 

 sible for the skill of a Megachile, who, while certainly fitted 

 for tunnelling the ground and for snipping circular and 

 elliptical pieces of suited dimensions from leaves with all a 

 tailor's precision, would find herself wofully unadapted for 

 the making of mortar and the building of nests, in imitations 

 of tunnels, out of pellets of mud that had to be moulded 

 into consistency and shape by the jaws of the builder. Pelo- 

 paeus alone, of all hymenopters, possesses the ability and 

 means of making such structures. Megachile, who is known 

 to occasionally build under the boards of the roof of a piazza, 

 might sometimes in her quest of a place appropriate the dis- 

 carded cells of some pre-existent Pelopaeus for nesting pur- 

 poses, but she runs a very great risk in so doing, for the 

 Mud-dauber does not always build a fresh home for her 

 treasures, save when there is a lack of the last year's struct- 

 ures. Old nests, when found, are put in speedy repair and 

 made to do as invaluable a service. 



