Published online by Cambridge University Press: 27 March 2009
In 1939, Pinous & Waddington reported tetraploid early cleavage stages of the rabbit after colchicine treatment of fertilized eggs in vitro. Chang (1944) inseminated rabbit does with sperm suspended in 1/1000 colchicine in 0·9% NaCl and noted a few abnormal young in the resulting litters. No chromosome counts were made, but Chang considered the possibility that colchicine had entered the egg and caused polyploidy. Using the same technique as Chang, Swedish workers have claimed the production of two adult triploid rabbits and one adult triploid pig (Häggqvist & Bane, 1950a, b, c, 1951; Melander, 1950, 1951). This Swedish work has been criticized (Beatty, 1951; Beatty & Fischberg, 1950; Becker, 1952–3; Hertwig, 1951; Nachtsheim, 1950; Rostand, 1951; Venge, 1953). Nevertheless, the technique is ingenious and the claim of great interest. The present note records preliminary attempts to extend the technique to cattle and to confirm the results in rabbits.