Stage II. Stage ITI. Stage IV. Stage V. 
Stage I. 
DIAGRAM I. 
li 
in 
Dark varieties. Light varieties. 
The accompanying diagram (I.) 
serves to show in a graphic 
manner the way in which the 
larve oscillated backwards and 
forwards between the dark and 
light varieties during the succes- 
sive stages. It must be under- 
stood that the dark varieties of 
(e.g.) Stage I. do not contrast 
with the light varieties of the 
same stage in the same marked 
manner as the two varieties of 
(e.g.) Stage IV. contrast together. 
Nevertheless the two varieties of 
the former were very different in 
this respect, and we should have 
expected that the darker larvee 
exhibited traces of the darkness 
which became more manifest in 
later stages. So also we might 
well have supposed that the 
single larva which exhibited 
marked indications of the dark 
borders in Stage II. would have 
been among the number of those 
in which this character was 
principally developed in the next 
stage, instead of among those in 
which it was least developed. 
It is much to be hoped that 
these surprising results will be 
carefully tested in other species. 
It would be well to keep a large 
number of individuals entirely 
separate, in order that the results 
may be analysed with greater 
accuracy. 
No variable colowr-relation be- 
tween these larve and their sur- 
roundings. — It is well known 
that the green form of these 
larvee often persists into the last 
stage. Thus I was assured that 
this variety is commoner than 
