| Abstract: | To study chromosomes in bull testes and their behavior at meiosis, a prefixation treatment with hypotonic solutions was used. After fixation, the material was squashed and stained with Feulgen's nucleal reaction. When needed, additional staining with iron-hematoxylin was feasible. The hypotonic Tyrode solutions of 10 to 20% normal strength were prepared according to A. Hughes (1952); the time of pretreatment was, in general, 15-30 min; fixation was made in glacial acetic acid-absolute alcohol (1:3) and Feulgen squash technic was carried out according to Schedule 5 of Darlington and La Cour (1947). Morphologic details were well preserved and photomicrographs of well-spread chromosomes in one plane were obtained easily. |
