Using the Han equation derived from the blob theory we obtain that the chains of wormlike polymers consist of one Kuhn statistical segment at the onset of excluded volume behavior. This holds when these polymers are dissolved in any solvent. This is in accordance with the predictions of Yamakawa-Stockmayer based on the statistical mechanics theory. Combining the same equation of the blob theory with a relation derived from the two-parameter theory, and accepting that at the onset of excluded volume behavior we have one Kuhn statistical segment for the wormlike polymers, we obtain a relation from which we calculate the statistical; segment length of these polymers from the K and a parameters of the Mark-Houwink-Sakurada equation. The obtained values are in good agreement with the values given in the literature. (C) 1997 American Institute of Physics. [S0021-9606(97)51547-9].