in metaphase by a solution of colchicine
:# Squashing the preparation on the slide forcing the chromosomes into a single plane
:# Cutting up a photomicrograph and arranging the result into an indisputable karyogram.

It took until 1956 for it to be generally accepted that the karyotype of man included only 46 chromosomes. The great apes have 48 chromosomes. Human chromosome 2 was