22 
MEMBRA GIJDJE. 
perfect insect, we need not consider it strange, that the early stages have received little 
attention. 
The metamorphosis of Membracidae is of the character styled incomplete, that is 
the pupal or nymph stage is in a measure locomotive. 
Probably there is a short season of rest before the final exuviation takes place. 
The process and time taken in the growth of the pronotum will prove an interesting 
subject for future observation. 
Few things are more difficult to realise than the fact, that some insects undergo even 
twenty moultings in five or six days.* Time is relative. We can have no adequate 
conception of the multitude of phenomema concerned in bringing about a simple chemi¬ 
cal change in a decomposition. Biological changes must be still more complex. 
The Pupa .—Histolysis consists in the apparent solution of previously existing 
organs, and formation of a kind of magma, out of which, through Histogenesis, new 
organs are built up. These portions of former existing tissues are believed to act as 
centres, from which new conditions arise. Members of the body and points of 
sensation are altered, perhaps in shape, in position, and even modified in function. 
Viallanes looks on this breaking-up of parts as a kind of inflammation, wherein 
only the pristine germs or imaginal discs survive destruction. But however this may 
prove to be true, a reconstruction of parts markedly takes place during the period of pupa¬ 
tion, and more particularly in those cases where metamorphosis is said to be complete. 
But though the pupae of Membracidse are active, and move from place to place at 
will, the two processes of solution and reconstruction are going on simultaneously. 
During the years between 1783 and 1794, H. J. Scheller prepared drawings and 
descriptions of three species of Membracidm, which he observed living on certain 
trees or low shrubs in Surinam. The names of these shrubs he unfortunately omits 
to give us, but as observations on the spot, in connection with life-history, are- 
important, I make no apology for giving through the kindness of a friend, the 
substance of the Dutch paper read in 1868 before the Ent. Soc. of the Netherlands, 
which treats of the metamorphoses of these insects. 
It may be said that up to this date nothing definite of these larval conditions has 
been published, and even now all trustworthy contributions will be acceptable, though 
they be meagre.f 
I venture therefore to reproduce enlarged drawings of these metamorphic forms, 
since the original life-sized figures are too small for general use. 
Like the editors of the above-named paper, I put forward no information as original 
in what follows. 
* See Burmeister; D. Sharp on Insecta, Camb. Univ, Press, part i. p. 166. 
t See footnote, p. 18. 
