Proceedings of the South African Philosophical Society. xii 
many insects are helped in perpetuating their race by means of pro- 
tective colouration pure and simple, or protective resemblance as an 
aid to aggression. 
This protective colouration must, however, be looked upon as 
relative. Were it perfect, it would follow that the insectivorous 
animals would have either disappeared entirely by this time, have 
become scarce, or have taken to another diet, as some of the present 
partly insectivorous, partly granivorous birds have done. But there 
is no evidence that the number of such animals is being reduced now, 
or that extinct forms have become extinct owing to the absence or 
want of protection afforded by colouration in so many insects, in 
connection with the various devices which I have endeavoured to 
explain. 
Let us now look at the imperfection of the hypothesis. I have 
laid stress, in speaking of protective resemblance, on the fact that: 
the insect is only protected when motionless. 
Methone becomes quite a conspicuous object when in motion ;. 
Precis tugela is easily seen when flying; Phasmus stellenboschus 
from invisible becomes quite evident. It is in the adult stage, how- 
ever, that flight and motion imperil the safety of the insect, and 
it is then that the majority of fatal cases occur, mostly owing to 
sexual attraction. 
Were it otherwise, why should not the Mantide and Phasnud@ be 
more numerous than they are. The former are probably not attacked 
by Ichneumons, or other parasitic insects, of which they would make 
a mouthful, but there is evidence to show that their egg-pod does not 
escape the attention of these numberless parasites, which are really 
the main factor in checking the increase in the multiplication of the 
species. 
If, from purely protective resemblance, we turn to warning colours, 
or to the assumption by edible insects of the colour of unpalat- 
able ones, better known by the name of the theory of mimicry, I am 
fain to think that the conclusions arrived at by many entomologists. 
who support this theory, are not warranted by a sufficient number of 
reliable observations. 
Trimen, in his Presidential Address to the Entomological Society 
of London in 1897, formulates the theory of mimicry as being brought. 
about by— 
a. Persecution of insectivorous foes. 
b. Possession of malodorous and distasteful juices of certain groups. 
~¢. Rejection or avoidance by foes of the insect provided with 
offensive juices, and loss occasioned to distasteful species by the 
attack of young and inexperienced enemies. 
