| Author Title Journal |
Phillips HM (1936) A cytological study of Macrostomum tuba Graff. Zool Anz 114:322-330 |
Abstract / Notes
The chromosome complement (2n=6, n=3) consists of 1 large pair, 1 medium pair, and 1 small pair; all have median attachment constrictions. The spermatozoa have 3-6 chromatin granules, depending upon the number of paired adjacent granules which have become so closely associated that they appear as 1 granule; it is suggested that each individual granule represents a chromatid. At the time the granules are formed, the spermatozoa may become associated with accessory or nurse cells. These cells have their origin as spermatogonia. A single nurse cell may serve as an anchorage for 1-5 spermatozoa. The oogonial divisions show 6 chromosomes. A large spindle bearing 3 chromosomes is present in the developing egg and apparently represents a maturation division.
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