1122 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XX. 



necessarily always in the same place, in a rather jagged way ; it 

 eats the shell as its first meal and then makes a bed of silk some- 

 where near the edge of the leaf ; changing this, after it becomes 

 bigger, for the midrib, stretched along which it always lies as in the 

 case of the larvae of the next family, the Pieridce. It is sluggish in 

 its movements at all periods of its existence, eats voraciously, grows 

 fast and wanders generally before pupating. The pupa is formed 

 aoainst a twig or small branch, the larva lying with its head 

 directed upwards, grasping the pad of silk, prepared before it 

 finally comes to the quiescent state, with its claspers and encir- 

 cling its body with a loop of the same, one end of which is attached 

 to the support about two-thirds of the distance from tail to head ; 

 both the attachments are very strong. When the pupa breaks 

 through the larval skin the cremastral hooks are wound into the 

 tail-pad and the loop supports the downward weight — the larva 

 having let go of the stem or twig some time before to fall back 

 against it — in segment 4/5 as a very general rule, though, owing 

 to same slight disturbance, the position may be somewhat displaced. 

 As the skin of the chrysalis becomes dried b}^ the air the part of 

 the loop tOTiching the body gets stuck to the surface and so keeps 

 the whole more or less secure. In some cases the loop is veiy 

 short, so that the pupa lies close up against the support with its 

 ventral surface ; in others it is long and the pupa swings freely on 

 the tail support. The length of the loop is characteristic of the 

 species or group. 



The Swallowtail caterpiller is easy to distinguish from any other 

 by the fact that it possesses an organ called an osmeterium 

 (meaning the " scented wonder"' or something of the sort) behind 

 the head. It is situated on the back in the membrane between 

 the head and the second segment and consists of a protrusible 

 single cylindrical stem, dividing into two longty conical branches 

 a short way from the origin, the whole thing not as long as the 

 greatest thickness of the larva. The branches are withdrawn back 

 into themselves from the top downwards, both finally being folded 

 into the main stem which is then "similarly drawn into itself. This 

 organ is shinv. thin-skinned and glutinous : it is variouslv coloured 



