Fitness in the Living World 313 



In animal, as well as in human warfare, the most effective 

 defense is a strong offense, and innumerable adaptations are 

 found for this purpose. Among these are many ferocious 

 modifications of teeth, such as tusks, sabers, and swords; 

 great developments of spurs, claws, pincers, and horns; 

 poisons and poison gases, such as the sting of the bee, the 

 poison of serpents and scorpions, the odors of bugs and 

 skunks. These last anticipate in many respects some of the 

 newest methods of gas warfare. But although many animals 

 have stings and spears, none has developed projectiles that 

 can be discharged at a distant mark. 



When one considers all these striking contrivances for 

 defense and offense, together with the appropriate behavior 

 by which they are accompanied, such as the well-known 

 habits of the rattlesnake, the porcupine, the opossum and 

 the skunk, the question inevitably arises whether lower 

 organisms have not discovered these means of protection 

 in a manner comparable to the way in which man has dis- 

 covered methods of defense and offense. 



3. Interorganismal Relations 



Another class of racial adaptations is found in certain 

 typical correlations between animals and plants, between 

 different species of animals or plants, and between different 

 individuals of the same species. Fifty-six years before 

 Charles Darwin published the "Origin of Species," Konrad 

 Sprengel (1793) published a work entitled "Das neue ent- 

 deckte Geheimniss der Natur" in which he proved that 

 flowers exist for the purpose of attracting insects in order 

 that the insects may carry pollen from flower to flower, thus 

 insuring cross fertilization. The contrivances by which 

 flowers attract insects, such as color, scent, and nectaries, 

 reach a climax in such plants as orchids, in which the nectary 



