84 ANDREW JACKSON HOWE. 



tion of neural knots about the mouth and throat, and 

 a neural cord extending along the ventral aspect of 

 the body ; and arranged on this cord at each segment 

 of the trunk is a pair of nerves to preside over the 

 movements of the wings, legs, feelers, or ovipositors. 

 The knots or ganglia located about the head and neck 

 constitute the knowing part of the animal. In these 

 knots of neural matter are developed degrees of in- 

 telligence that, in some features, rival the wisdom of 

 man. It is flippantly declared that these articulate 

 creatures are governed by instinct, and that they 

 have no mind that is improved by experience, or is 

 educable, but every trained observer has found that 

 instinctive knowledge, so called, is sharpened by ex- 

 perience, and often improved by the vicissitudes of 

 fortune. The intelligent principle resident in a set 

 of somewhat scattered neural ganglia may not be as 

 teachable and comprehensive as that developed in a 

 more compact nerve-mass, as the encephalon or brain 

 of the higher animals, yet it is both tractable and im- 

 provable. The spider has no brain, yet the creature 

 thinks, makes snares to net prey, lies in ambush, re- 

 pairs broken gins, changes hunting places when game 

 becomes scarce, or any thing has seriously interfered 

 with trapping operations in an old haunt. 



A single neural knot or a pair of ganglia, with 

 riervules extending to and from this center of action, 

 constitutes the simplest demonstrable apparatus for 

 generating intelligence ; and four or five pairs of gan- 

 glia in a group about the head make a very strong 

 battery of neural activity. As a rule, invertebrate 

 animals are small, yet the octopus, or cuttle fish, is 

 sometimes monstrous in size, and generally very intel- 

 ligent. The centipede has more pairs of ganglia than 



