Relative growth of leg segments of the German cockroach, Blattella germanica

Measurements were made on the lengths of all the nine leg segments--coxa, trochanter, femur, tibia, and five tarsomeres--for three pairs of legs of both sexes throughout postembryonic stages. "Growth contours" were constructed to outline the temporal and spatial patterns of growth. Growth center was located in or near the 1st tarsomere of all the three pairs of legs, whereas growth depression was found in the 4th and 5th tarsomeres. Consequently, the relative length of the 1st tarsomere increased with the advance of the stage, while that of the 4th and 5th tarsomeres decreased. Ratios were calculated between the lengths of any dual combinations of the nine segments. Among these ratios, the tibia to femur ratio most distinctly changed with the kinds of legs. The 1st to the 5th tarsomere ratio most extensively increased with stage. Differences in relative length between the fore-, mid- and hindleg were examined for each of the nine segments. The differences were largest in the 1st tarsomere and tended to decrease toward the segments of both ends of the leg. The differences in coxa, trochanter, femur, and tibia tended to increase with stage, whereas those in five tarsomeres showed a decreasing tendency.