Electron microscopic analysis of the banding pattern in the salivary gland chromosomes of Drosophila melanogaster

An electron microscopic analysis of the divisions 21 and 22 in the salivary gland chromosome 2L of Drosophilo melanogosterreveals at least 88 recognizable bands. This number is 35% more than given (65) in the revised light microscopic map of P. N. Bridges and 83% more than drawn by C. B. Bridges (48) in his original light microscopic map for these divisions. The number and definition of double bands in comparison with pairs of equal bands appears to be difficult to establish in electron microscopy.