The Histology of a Very Large Insect, Macropanesthia Rhinocerus Sauss. (Blattidae)

Abstract

The internal anatomy and histology of a large cockroach, Macropanesthiarhinoceros Sauss. (weight, approximately 20 g.), has been compared with thatof a relatively small one, Blattella germanica (L.) (weight, approximately 0.06g. ). The observations have been considered in the light of Rensch's generalizationsconcerning histological changes in relation to body size and to thefactors which may limit the size of insects. It is concluded that gravity,diffusion, and area for secretion and absorption are not factors limiting thesize of Macropanesthia. The specializations observed in Macropanesthia arerelated to its burrowing habit and its food rather than to its large size.