260 OBSERVATIONS ON INSECTS. 



appears to have been broken off in the fall : when 

 complete, the whole must have been nearly the size 

 of a child's head. What remains is of a somewhat 

 hemispheric form, approaching to pear-shaped at its 

 upper extremity where united to the twigs ; it is 

 about six inches in diameter, and nearly eighteen 

 in circumference. The outer case is formed of seve- 

 ral layers of a papyraceous substance, easily separ- 

 able one from another, and, on the whole, very simi- 

 lar to the external covering of the nest of the com- 

 mon wasp. On examining this substance under a 

 high lens, it appears to be made up of mirtute fila- 

 ments irregularly matted together, and afterwards 

 besmeared with some viscous fluid causing them to 

 adhere. Within the nest were four tiers of cells 

 one above another : the lowermost tier alone, which 

 was much the smallest, consisting of upwards of one 

 hundred and thirty. Some of these cells are much 

 bigger than others. Many of them were open, 

 and contained larvae ; others had the mouths sealed 

 up, and contained pupae, or the perfect insect just 

 ready for exclusion. 



It seems remarkable that, at this advanced period 

 of the year, so large a portion of the brood should 

 be still in the immature state. One can hardly ima- 

 gine that the whole would have completed their 

 metamorphosis before winter, had the nest remained 

 undisturbed. Probably, however, nidification con- 

 tinues to go on till the cold puts a check to further 

 operations, when those larvae, which are the latest in 

 hatching, must necessarily perish. 



