Chromosome preparations were photographed under an oil-
immersion (100) lens and the coordinates of good preparations
were noted. Preparations were photographed under oil-immersion,
using a Zeiss precision interference filter (No. 467808) to give
a monochromatic green light. Kodak HQ high-contrast microfilm
was used, and prints were prepared at a magnification of 3000.
Photographs were either cut up and the chromosomes arranged as
karyotypes before being scanned into a computer, or were scanned
into a computer uncut. In both cases the karyotypes were finally
arranged using Adobe Photoshop.