xxxvi THE ANIMAL KINGDOM. 



of smell. The carrion beetles scent their booty afar off ; the ants, the moths, all the 

 insects attracted to flowers by the smell of the lioney in them, evidently have well de- 

 veloped organs of smell." 



The internal structure of the brain of the ant, the bee, as well as the locust and other 

 insects has been found to be unexpectedly complex, when compared with that of the 

 higher worms and even the higher Ci'ustacea, such as the lobster and cray fish. The 

 brain of insects is a much more complicated organ than any of the succeeding ganglia, 

 consisting more exclusively of sensory cells and nei-vous threads than any succeeding 

 ones, though the subcEsophageal one is also complex, consisting of sensory as well as 

 motor ganglia, since this ganglion sends off nerves of special sense to the organs of 

 taste and smell situated in tlie mouth-appendages. The third thoracic ganglion is also, 

 without doubt, a complex one, as, in the locusts, the auditory nerves jiass from it to the 

 ears, which are situated at the base of the abdomen. But in the gi-een grasshoppers, 

 such as the katydids and their allies, whose ears are situated in their fore legs, the first 

 thoracic ganglion is a complex one. In the cockroach and in Leptis {Chryso^nla), a 

 common fly, the caudal appendages bear what are probably olfactory organs, and as 

 these jjarts are undoubtedly supplied from the last abdominal ganglion, this is proba- 

 bly composed of sensory and motor ganglion-cells ; so that we have in the ganglionated 

 cord of insects a series of brains, as it were, running from head to tail, and thus in a 

 still stronger sense than in Vertebrates the entire nervous system, and not the brain 

 alone, is the organ of the mind of the insect. 



To briefly describe the brain of the locust, an insect not higli in the scale, it is a 

 double ganglion, but structurally entirely different fi-om, and far more complicated than, 

 the other ganglia of the nervous system. The cerebral lobes possess a ' central body,' 

 and in each hemisphere is a ' mushroom body ; ' besides the main cerebral lobes, the 

 brain has also a pair of optic lobes and optic ganglia, and olfactory or antennal lobes, 

 and these lobes have their connecting and commissural nerve-fibres, not found in the 

 other ganglia. 



The locust's brain appears to be as highly developed as that of the majority of in- 

 sects, but that of the ant and the bee is more complicated than in other winged insects, 

 owing to the much greater complexity of the folds of the calicos or disk-like bodies 

 capping the double stalk of the mushroom body. Now the ants, wasps, and bees 

 are pre-eminently social animals, and we see by the structure of the brain why, in 

 point of intelligence, they may exceed in mental development even the fishes, rep- 

 tiles, and other lower vertebrates, and almost rival the birds in instinctive and 

 rational acts. 



Experiments and anecdotes bearing upon the intelligence of ants, have been 

 widely circulated in the works of Lincecum, McCook, Lubbock, Darwin, and Romanes, 

 space not allowing us to reproduce them. Ants have the sense of sight and of 

 scent and taste well developed, but the sense of hearing is feeble, sounds of various 

 kinds not producing any effect upon them : their antennae are not, then, as in some 

 insects, organs of hearing or smell, but have a delicate sense of touch, and, indeed, 

 are the most important of sense organs to them. The sense of direction, the power 

 of memory, are highly developed, and they perliaps are not destitute of the tenderer 

 emotions, individuals being known to display sympathy for their wounded compan- 

 ions or healthy friends in distress. Ants also have the power of communicating with 

 one another, and they are susceptible of education. The young ant is led about tlie 

 nest and " trained to a knowledge of domestic duties, especially in the care of the 



