1014 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XIX. 



Animals that are protectively coloured are in the habit of remaining motion- 

 less when alarmed, thus unconsciously giving full play to their special safe 

 guard. 



Again reading Mr. Selous' account of the manner in which lions stalk their 

 prey must convince one that these carnivora owe a great debt to the colour 

 of theii- skin and, what is more, that they understand how to take full advan- 

 tage of the fact. 



To contend that colouration gives complete protection under all conditions 

 involvts one in the following reductio ad absurdum. The natural corollary to 

 the contention is that carnivorous animals would never secure any prey, 

 except by mere chance, and therefore, would rapidly disappear through starv- 

 ation, while at the same time, no herbivorous animal would ever escape from 

 a protectively coloured beast of prey and they too would all succumb. 



It is to be presumed that the opponents of natural selection (for that is 

 what it amounts to) admit that colouration and markings in animals are the 

 result of a process of evolution and that the instinct to remain perfectly still 

 under danger is likewise brought about of evolution. Then, believing as they 

 do in the environment theory, they must hold that the two characteristics 

 were evolved separately and unconnectedly and yet eventually were united, 

 for they are shared in the same, or almost the same-degree by every individ- 

 ual of the same species. 



This is surely too much to concede. The two traits must have been 

 evolved together and the one as a complement to the other, as each apart 

 would be more or less useless, if not often harmful. 



The theory of colouring induced by environment seems to me necessarily to 

 exclude variation in colouration. Once a species is coloured in harmony with 

 its surroundings and as a result of them, they would not be able to vary much 

 thereafter, as the same influence, it must be presumed, would tend to bring 

 them baciv to the lype. 



But there is nothing more certain than the fact that variations constantly 

 do occur, which variations if harmful will again disappear and if beneficial 

 will endure and become fixed into new types. If the new type has a distinct 

 advantage over the parent the latter will tend to disappear, otherwise the 

 variation becomes a well defined race or variety, and in course of time draws 

 further and more definitely apart and evolves into a new species — possibly 

 eventually into a new genus. 



With colouration by environment new species could only arise when some 

 of the individuals of a species migrated to new regions, the environments of 

 which w^ould differ to a certain extent from that they have left. But, as a 

 matter of fact, we know that new species arise in the same localities, the 

 original type often enduring side by side with the new. 



It must not be forgotten that, as a rule, the evolutionary process is slow 

 and spread over a period of very many years. 



Mr. Selous states that zebras, irapala antelopes, giraffes, etc., are very striking 



