THE ORGANIZATION OF INSECT SOCIETIES 



435 



(Fig. 154), all indicate remarkable be- 

 havior responses to spatial factors and to 

 gravitation. 



The fact that the geometrical pattern is 

 rebuilt if destroyed is of interest. Hingston 

 (1932) removed the chevron-shaped rain- 

 shedding ridges on the tree trunk above the 

 nest of Constrictotermes cavifrons. After a 

 few days, during which rain water made the 

 upper part of the nest soggy, the workers 

 reconstructed the ridges and in six weeks 

 had rebuilt eight out of the eighteen origi- 

 nally destroyed. Hingston interpreted this 

 behavior to be an example of intelligence, 

 but inasmuch as the species-specific archi- 

 tectural pattern is surely heredity and is 

 transmitted by the reproductives, which do 

 not build nests, to their sterile worker off- 

 spring, such reconstruction of replicative 

 structures seems best analogized with the 

 regeneration of somatic tissue in the 

 organism. 



In any case, we find social behavior pro- 

 ducing structures that illustrate such 

 morphological principles as polarity, fields, 

 gradients, spherical symmetry, radial sym- 

 metry, bilateral symmetry, polyisomerism 

 or replication, anisomerism or specialized 

 modification of polyisomerous structures, 

 genetic homology, functional analogy, con- 

 vergence, and regeneration. Of course, 

 these principles are strictly analogous in the 

 architectural behavior of the sterile castes of 

 the social insects and in the physiological 

 and growth reactions of the cells of a multi- 

 cellular organism, but such analogous 

 similarities between the organism and the 

 supra-organism cannot be lightly dismissed 

 by pointing out differences in mechanisms 

 or in functions. It would be like pointing 

 out the physiological, genetic, and func- 

 tional differences in the sex biology of the 

 flowering plant, earthworm, insect, and 

 man, and refusing to recognize the common 

 denominators that together make up our 

 concept of sex and sex function. The re- 

 fusal to accept analogical comparisons as a 

 part of scientific method would eliminate 

 the comparative study of convergent social 

 systems in insects— for example, that of ants 

 and termites. 



In opposition to this attitude against 

 analogical reasoning, we hold that the 

 synthesis growing out of the comparison of 

 organism and supra-organism helps to 

 elucidate fundamental principles and is a 



challenge leading to further analysis and 

 understanding of biological mechanisms 

 (see Schneirla, 1946, for an opposed view- 

 point). The thorough investigation of 

 similarities (homologous and analogous) 

 and differences, both of mechanism and 

 function, assists in gaining realistic and 

 scientific perspective. 



The insect society forms a closer analogue 

 to the multicellular organism than does 

 human society. The reasons for this differ- 

 ence between the two social types seem to 

 rest upon the evolution of physiological and 

 genetic mechanisms among the insects, con- 

 trasting with the evolution of plastic be- 

 havior leading to intelhgence and reasoning 

 among the vertebrates, particularly among 

 the mammals. Thus we find physiological 

 mechanisms and instinctive behavior more 

 marked in insect social life, whereas condi- 

 tioned behavior, learning, and finally sym- 

 boUc learning and a high degree of reason- 

 ing and psychological division of labor are 

 characteristic of human society. Human 

 society is manifestly a phylogenetic de- 

 velopment of the group behavior of the 

 higher vertebrates in its dependence upon 

 the cerebral cortex and social hierarchy as 

 well as upon trophallaxis. 



These differences are probably not 

 wholly quaUtative. Insects exhibit some 

 capacity for learning. Men exhibit some 

 hereditary behavior patterns. Both indicate 

 a profound influence from antecedent 

 sexual, famihal, and group adjustments from 

 which many strictly social facilitations 

 emerge. It is even an open question whether 

 plastic and hereditary behavior are funda- 

 mentally distinct. There are many indica- 

 tions that both aspects of behavior have a 

 common basis in the physiology of the 

 nervous system, and certainly any single 

 act of either a man or of an ant may in- 

 corporate both instinct and conditioned 

 behavior. 



In conclusion, the complex group func- 

 tions and integrations of the social insects 

 afford extreme examples of intraspecies co- 

 ordination and cooperation. The concept of 

 biological unity of populations is securely 

 attested and establishes the population 

 svstem as a fundamental biological imit 

 comparable in theoretical importance to 

 other basic units such as ♦^'^e cell or the 

 individual organism. 



