Osservazioni sulla cariologia di bombina

Abstract

Diploid set of B. bomhina and B, varicgata is constituted by 12 chromosome pairs strictly corresponding in both sexes and in both species; consequently, Bomhina does not show cylologically distinguishable hetcrochromosomcs.Peculiar figures in intestinal cells at prophase of B. bomhina seem to show a close relation between nucleolar organizers and the heterochroinatic zones on the 7th pair.Some stages of the male mciosis in B. varicgata arc described expccially in relation to the presence of a major coil in melapliasc 1 or perhaps in dyaki-ncsis, and not in former stages of the first mciotic division, on the contrary that in other Anurans.After some discussion on the problem, the A. makes comparison between oocyte and spermatocyte hivalcns at diplotcnc of B. varicgata: in both sexes chiasmata are not restricted in their distribution, but their number seems higher in the female sex. © 1965 Taylor & Francis Group, LLC.