The spermatogenesis of acaris habena linton
Text from pages 2-3: "In the development of spermatozoa, there are first differentiated in the embryo the primordial germ cells. These divide and subdivide until a large number of cells, known as spermatogonia, are formed. Then the cells begin to increase in size and following this growth period, there are two maturation divisions during which the chromatin content becomes reduced one half. The cells produced by these divisions become immediately the functional germ cells, or spermatozoa. It is the behavior of the chromosomes of Ascaris habena during the maturation divisions that is discussed in the following pages."