For example, in Drosophila, as in many other insects, there are two X Chromosomes in the cells of the female and one X chromosome in the cells of the male.
"Sex-linked Inheritance in Drosophila"
Thomas Hunt Morgan Calvin B. Bridges
Next we see what appears to be a rolled-up ribbon analogous to the chromatin band, which soon breaks into fragments analogous to the Chromosomes.
"The Mechanism of Life"
Stéphane Leduc
So the number of Chromosomes for the species is kept the same or constant.
"The Glands Regulating Personality"
Louis Berman, M.D.