30 THE TRANSFORMATIONS. 



3. Eggs laid by virgin females yielded females only 

 with Hemicliroa rufa, Eriocampa ovaia, Poecilosoma 

 pulveratum, and Croesus varus. 



4. Eggs were laid by virgin females of Phyllotoma 

 nemorata, Ph. vagans, Taxonus glabratus, Strongylo- 

 gaster cingulatus, Nematus salicivorus, but no insects 

 were bred from them. 



2. THE TRANSFORMATIONS. 



The Egg. 



The egg is ovoid and longer than broad, with some- 

 times a curve on one side. The colour is white, occa- 

 sionally with a bluish tinge or slightly greenish. The 

 usual nidus for the egg is the leaf, but the manner in 

 which the eggs are deposited on it is very varied. 

 Very often they are scattered irregularly over the 

 epidermis (Nematus miliaris), or they may be placed 

 along the edge, the projecting part of the leaf being 

 used for this end by Hemicliroa alni ; and again, they 

 may be arranged along one or other of the veins as 

 with Nematus rilesii. Some species sink the eggs in 

 a hole in the epidermis, while others merely glue them 

 to it. A few species place them in a clump (N. 

 pavidus), but mostly they are separated from each 

 other when several are laid on the same leaf. One or 

 two of the leaf miners deposit only one egg on a leaf. 

 Many widely divergent species place their eggs in the 

 petiole, in which they may be either arranged in a 

 single or double row. And in connection with this, it 

 is worthy of being noted that the species having this 

 habit have the ovipositor very strong and broad, e.g. 

 Hylotoma pagana, Hemicliroa rufa, Nematus luteus: 

 Most of the gall-making species lay their eggs in the 

 leaf-buds before they have expanded, and in some 

 instances the growth of the gall and of the leaf goes 

 on at the same time. 



