CLASSIFICATION OF ANIMAL AGGREGATIONS 25 



given by the termites, where sexually mature males and females of 

 one or more grades occur in the same nest with soldiers and 

 workers. 



(4) In a patropacdium the male remains with his offspring for 

 some time. Schulz (1926), in his analysis of the situation in the 

 brooding stickleback fish {Gastcrosteus aculeatits and G. pungitius), 

 concludes that the value to the male is in the psychological realm, and 

 quotes Deegener with approval as saying that the nest and young are 

 of lively interest to the male stickleback, their loss is a misfortune, 

 and the nesting and brooding phenomena are a source of inner peace. 

 Obviously, such assertions are not susceptible of demonstration. To 

 the eggs there is the benefit of added certainty of fertilization, of 

 protection from other fishes, of aeration, with resulting protection 

 from fungus growth; while the young find a favorable place for 

 development, passive protection by the nest, and active protection 

 by the guarding male. The relation between eggs and young and the 

 brooding male is essential rather than accidental, and therefore 

 forms a true society. It is reciprocal, and the female is not concerned 

 after the eggs are laid; therefore a patropacdium, which had its 

 origin in a polygamous connubium existing merely as a mating rela- 

 tionship, but this connubium is an association rather than a society. 

 If the male dies, the society becomes a simple sympaedium, which 

 would be accidental in nature, since the association of the young has 

 no value for them. The relation of the young to the nest has a syn- 

 chorium factor. The existence of the patropacdium is necessary for 

 the well-being of the eggs but not of the young fishes. The relations 

 between the males of the large- and small-mouthed black bass, the 

 bullheads, and the fresh- water dogfish {Amia calva) and their nests 

 and young give an opportunity for similar analyses. 



b) Irreciprocal families are those in which the social values rest 

 only with the young. 



(i) Gynopaedia of this sort are to be found in the leeches (Glossi- 

 phonia), according to Deegener; but Schulz detected evidence which 

 led him to conclude that the female leech is somewhat interested in 

 her eggs, and on this account he places these leech gynopaedia among 

 the reciprocal societies. Similarly, careful observation might show 



