NOTE ON THE COLORATION OF INSECTS. 3 
and arrived at results so interesting that I have published them in a 
work entitled Observations on the Coloration of Insects, which appeared 
in 1897. 
My conclusion was that observed facts do not allow us to admit that 
this phenomenon can be attributed exclusively to ‘‘ Darwinian selec- 
tion,’ but that, on the contrary, primitive coloration is due to influences 
which are entirely independent of the welfare of the animal, and some- 
times even contrary to its needs. The adaptation to the demands of 
the creature is a secondary action and this only is brought about in 
accordance with the laws of selection. 
Naturalists, misled by Darwin’s ingenious theory, shook their heads, 
and it was especially in England that I met the most serious opposi- 
tion. My opponents did not deny the facts referred to, but raised the 
objection that we know too little of the various phases of the phylo- 
genetic development of the species to be in a position to pronounce a 
verdict upon the utility of the qualities which we observe. 
I thoroughly agree that we are far from appreciating the influence 
of external causes upon the modification of the species, but on a minute 
examination of colour, it is impossible to admit that it is the result of 
a slow and eradual modification such as selection demands. 
Of the numerous examples referred to in my work, I choose one to 
illustrate my point. Mastax semicaeca, alittle grasshopper of the family 
Acridiodea, and a native of the Upper Amazons, is of a dark olive colour. 
The uniformity of this colour is broken up by a lateral yellow band of 
equal breadth, which runs the entire length of the insect. It begins at 
the head, crosses the lateral lobes of the pronotum and continues alone 
the abdomen, regardless of the position and arrangement of the different 
organs. This band has caught the lower half of the eyes, and I 
think that the visual powers of the insect are thereby impaired. An 
objection could be raised that at a certain epoch the diminution of this 
faculty was advantageous to the insect, and there are several cases of a 
modification of the visual power, insects which live in caves, for 
example; but in these cases it can be shown that this result is obtained 
by a gradual obliteration of the eyes. It is the natural métnod 
responding to the action of selection. The application of a bandage is 
usual in the operating chamber of an oculist, but does not occur in 
biological genesis. 
May I be allowed to adda point that is very liable to escape observa- 
tion, a minute question of coloration in the front leg of Hierodula 
notata, a Mantis from Borneo? ‘The front legs are not adapted for 
walking, but are used by these voracious animals as weapons for seizing 
their prey. When in a state of repose there can be seen in the middle 
of the under surface of the femur a black round spot. When the foot 
is extended this spot is broken. One part of the black colouring is on 
the femur, the other on the spines of the tibia, which, in repose, is 
closed against the femur. The round black spot is formed, therefore, 
by a combination of two organs in a certain fixed position. If this 
spot is produced by natural selection, and if it is developed by an action 
which is part and parcel of the animal, it follows that organs, entirely 
distinct in their nature, are made use of to produce a black spot. 
Further, if this spot had been misplaced by a single millimétre, it 
would have fallen entirely upon the surface of the femur and its pro- 
duction would have been far more simple. According to my theory 
that coloration is a property emanating from an external power that 
