ANTS AND ANT LIFE. 47 



far exceeds that of man in development as to its bulk. 

 None the less are the cerebral ganglia of the ant which 

 ganglia in invertebrate animals take the place of the brain 

 proper to the vertebrate no larger in reality than the 

 quarter of the head of a pin, and the size again is of course 

 different in the different species. " Under this point of 

 view," says Darwin (" Descent of Man," ed. 1875, p. 54), 

 " the brain of an ant is one of the most marvellous atoms 

 of matter in the world, perhaps more so than the brain of a 

 man." This fact shows at the same time " that there may 

 be extraordinary mental activity with an extremely small 

 absolute mass of nervous matter." 



But the brain of the ant, not only in its relative size, but 

 also in general shape and construction, is superior to that of 

 all other insects, and most resembles that of hive-bees and 

 the other socially-living insects of the same genus. At first 

 sight we are startled to find two large projecting hemispheres, 

 as in higher animals. If these are put aside, we find Dujar- 

 din's two " stalked bodies," surrounded by a cellular enve- 

 lope, which gives to each hemisphere its rounded appear- 

 ance. These stalked bodies are not so much developed in, 

 any other insect as in the ant, and are generally found to be 

 either rudimentary or arrested. Under these is found the 

 primitive ganglionic cerebral structure, which is common 

 to all insects. It is a single oblique body, in the middle of 

 a somewhat convoluted mass, and is covered by the lower 

 part of the stalked bodies. Right and left lie the optic 

 lobes, or centres of origin of the optic nerve ; in front and 

 beneath, the olfactory lobes. 



The stalked bodies are not, as has been thought, centres 

 for the so-called ocelli, or accessory eyes, but stand in a very 

 decided relation to intelligence. They are very large in the 

 branches of the genus Formica, which includes the most 

 intelligent species ; they are largest in the most intelligent 

 of all the ants, the Formica sanguined, or blood-red ants, 

 and in the turf-ants, Formica pratensis. It is veiy remark- 

 able also, that the neuter workers as far excel the winged 

 males and females in the size and development of their 

 stalked bodies, as they do in the amount of their intelligence. 

 These bodies are the smallest in the unintelligent males. 



It may be added that Treviranus had already proved that 

 all the social Hyrnenoptera, to which genus belong bees, 



