Abstract
From an analysis of 72 nuclei at pachytene in three species of Neodiprion it is shown (1) that the rate of pairing is independent of chromosome size, (2) the nucleolar chromosomes are at no disadvantage in pairing, and (3) the incompletions observed are the result of an interruption by fixation of the process of zygotene pairing. It is concluded that there is no fixed relationship between the intimacy of telophase association and pachytene pairing, the degree of relational coiling at diplotene, and the distribution of chiasmata at metaphase.