1470 The Zoologist — December, J 808. 



they descended to the ground, where they formed small egg-shaped 

 elliptical cocoons just below the surface. These cocoons were entirely 1 

 covered with little grains of earth and sand, which were tightly 

 cemented to them (fig. 4) : on these being detached the cocoon was 

 found to be shining coppery black, and, with the exception of some 

 loose threads, quite smooth. These cocoons did not produce me any 

 living imago : alter waiting in expectation a considerable time I deter- 

 mined, in July, 1860, to cut open the cocoons. Id the greater number 

 1 found dried-up larvae, but in two cocoons were dried-up pupae, which 

 had been just ready to emerge, and had even partly cast off the last 

 thin integument. The colouring was very recognisable, so that the 

 species of sawfly could be pretty clearly determined. 



It was not until the 24th of May, 1863, that I was able to continue 

 my observation of this insect. I found on the same poplar tree a leaf 

 eaten entirely through, and in the state represented at fig. 6, a piece in 

 the middle had been left upon which were seen a number of empty 

 egg-shells: they were placed somewhat irregularly close together, but 

 had all the same elliptical form, and were lying in the same direction; 

 they are represented, slightly magnified, at fig. 7. 1 found some very 

 young larva? on that part of the leaf which had been eaten into holes, 

 which larva; were, apparently, about four days old; they were dark 

 green or blackish, with black heads: one is represented in outline at 

 fig. 8. Oh the 31st of the same month they had moulted, probably 

 for the second time, and were of the size and appearance of our 

 figure 9, and, as far as the general coloration and markings were con- 

 cerned, had completely acquired the appearance represented at our 

 fig. 1. The only distinction was that the green colour was not so 

 much inclined towards bluish gray, but more nearly approached a 

 pure green. 



I daily visited and examined my nurslings, and on the 3rd of June 

 1 calculated that they would require eight or ten days before they were 

 full grown. I was therefore not a little surprised when, on the -4th of 

 June, I found that, with the exception of one individual, my whole 

 sawfly family had disappeared. 1 thought at first that some hungry 

 sparrow or titmouse had accidentally discovered the colony and had 

 devoured them ; it seemed to me strange that one individual should 

 have been left, as birds, when once they have made such a discovery, 

 do not usually leave anything remaining: however, 1 took the little 

 animal that had been left and put it into a tin box with some earth 

 and a couple of leaves : 1 then discovered that the whole family must 



