92 AN INTRODUCTION TO SCIENCE 



"progressive transmutation," that for all practical purposes 

 it is the starting-point of the "new biology." And, although 

 Wallace shares equally with Darwin the credit of formu- 

 lating the law, the main burden of its proof was undertaken 

 by Darwin. There can be little doubt that a century 

 hence, when minor details have been forgotten, the progress 

 marked by the enunciation of the theory of Natural Selec- 

 tion will be regarded as the greatest event in the history of 

 Science, the most remarkable step forward ever taken. 



It is difficult to exaggerate the magnitude of the change 

 which the theory of Natural Selection brought into the 

 naturalist's attitude of mind towards the subjects of his 

 study. It gave them life. The wax-work figures which 

 peopled his world began to move. Instead of each indi- 

 vidual form standing still, finished, immutable, it is seen to 

 be coming out of a past and progressing towards a future. 

 It is no longer a perfected thing doing, as its ancestors have 

 done, the work for which it was designed ; but it is strug- 

 gling towards perfection amidst a multitude of competitors. 

 As its progress becomes faster, its species spreads over the 

 earth, it falls behind its neighbours in capacity for adapta- 

 tion, it will shrink into an insignificant remnant. The 

 stronger plants are ousting the weaker from soil and sun- 

 shine. Defenceless plants and animals are growing cleverer 

 in eluding their enemies. Predatory animals are becoming 

 more cunning in discovering the wiles of their prey, stronger 

 in jaw and claw and clasp of limb to pierce their armour. 

 The existence of every living thing depends upon its being 

 able to obtain its food and to resist its enemies. The 

 slightest balance in its favor means perpetuation, the least 

 deficiency leads to extinction. Is the shell of a mollusc 

 strong enough to resist the crushing grip of a lobster's claw ? 

 Will a lobster's carapace withstand the horny jaw of an 

 octopus when its eight arms envelop it in their paralyzing 

 embrace ? Can the octopus or cuttle-fish hide its soft body 

 from the dog-fish in search of food by suddenly changing 



