Distribution of Number of Segments in Earthworms and its Significance

Abstract

DURING the course of an investigation into the relations between earthworms and the fertility of the soil, it has been found necessary to study the biology of the several species found in grassland in some detail since, in spite of their natural abundance, possible importance and extreme commonness as a type in zoological classes, very little is known about their biology, distribution on different types of soil, seasonal activities, etc. One of the factors making such a study difficult has been the fact that the specific characters are largely based on the position of the clitellum and tubercula pubertatis, which only appear at the onset of sexual maturity. Thus in a representative sample of worms only a small proportion are identifiable.