194, Mr. B. T. Lowne on 
or both sexes occasionally produce wings, I think we see 
forms intermediate between apterous, and winged sexually 
mature ones. 
Two views may be taken of the significance of these 
facts. We may see a transitional condition between a 
larva like progenitor and an imaginal descendant, or we 
may see a transition from a winged to an apterous per- 
fect insect. 
My own belief is, that we see a transition from a 
winged to an apterous mature form, and this belief is 
based on the following facts. 
Firstly ; that larvee have been observed copulating, and 
that there is a decided tendency in many animals for the 
sexual organs to attain maturity before the animal attains 
all its adult characters. 
Secondly; the rare appearance of wings in many He- 
mipterd, especially in the female of Sphyracephalus 
ambulans, appears more like reversion to a lost ancestral 
form than a tendency to develop a winged one. 
Thirdly; because the sexual organs of insects first 
appear at a very early period of hfe, and undergo, in 
some instances at least, gradual development, until the 
insect arrives at maturity, although all the other organs 
undergo a very remarkable metamorphosis. Indeed there 
is good reason to believe, that the remarkable larval re- 
production of Cecicdomyide, depends on the premature 
development of the sexual organs in the larva. 
On the other hand, the principal objection to this view 
that has occurred to my mind is, that the larva of the 
Ametabola is usually believed to have existed in a mature 
condition before any winged insects had been developed. 
Fritz Miiller says, ‘‘It seems to me, that valid reasons 
may be brought up in favour of the opinion, that the 
most ancient insects approached more nearly to the 
existing Orthoptera, and, perhaps, to the wingless Blat- 
tide, than to any other existing order.” And although 
Gerstiicker and others have shown, very conclusively to 
my mind, that the larval forms of the Metabola are not 
direct or inherited, but indirect or acquired, I am not 
aware that any one has advanced this hypothesis with 
regard to the metamorphosis of the Ametabola. 
