1868.] 



161 



single egg remaining in it— thus showing that she must have deposited 

 by far the greater portion of her burden before her capture. 



On 10th September, he shut up another female in the same way, 

 which also died on the fourth day, without depositing any eggs, and on 

 dissection was found to contain a quantity of eggs, with shells, but 

 not fully developed. On 1 6th September, he shut up a third female, 

 which lived five days, and being then at the point of expiring, was 

 pinned to a cork, when she laid three eggs ; on dissection, 160 well- 

 developed eggs were found in her, and carefully extracted. On 24ith 

 September, a fourth female was shut up ; she died on the third day, 

 and when opened had no eggs in her. 



Of the eight eggs he obtained from the first female, Mr. D'Orville 

 gave me five, which, to my great sorrow, shrivelled up ; from two of the 

 remaining three, larvae were produced on September 26th, a period of 

 something less than three weeks having elapsed since their deposition ; 

 none of the other eggs, whether laid or extracted, proved good. 



These little larvae— white in colour, with long, black caudal horns, 

 were put on a growing plant of Convolvulus arvensis, and during the 

 following night placed themselves in position on the under-side of a 

 leaf, and ate little holes through it ; however, they soon died, one after 

 four days', and the other after ten days' existence. 



To these notes made recently, Mr. D'Orville adds one made in 1859. 

 In that year he captured nineteen moths, and from one of the females 

 obtained a single egg ; the larva from which was hatched on September 

 27th, and after feeding ten days on Convolvulus arvensis, died in its 

 first moult. And on October 13th of the same year he found a larva 

 about one-third grown, in a potato field, on a spot where Convolvulm 

 arvensis was entangled with the potato haulms ; it was covered with 

 wet dirt, as if it had been in hiding under the earth. A few days later, 

 a larger larva, more than two-thirds grown, but dead, was found in a 

 similar situation, and brought to me. 



From these facts Mr. D'Orville draws the following conclusions : 

 first, that the imago, in this respect unlike S. ligustri, and the three 

 species of Smerinthus, does not emerge from the pupa with ova fully 

 developed, but rather in a very unformed state, and that they become 

 gradually formed in the body of the female — perhaps after impregnation 

 has taken place. And here I may notice that the egg of convolvuli is 

 not more than tw^o-fifths of the size of the egg of ligustri, so that even 

 when a female has her full number (somewhat between 200 and 250) 

 ready for extrusion, she would by no means show so stout a figure as a 

 female of ligustri in similar circumstances. 



