Changes in embryonic cell frequencies in the germinative and immature regions of Hymenolepis citelli during development.

This study traces the growth rate of Hymenolepis citelli and correlates such growth to the relative frequency of the only mitotically active cell found in the germinative and immature regions of the cestode. The abundance of this cell, termed the germinative cell, was very high during the early logarithmic growth phase of the cestode and decreased just prior to patency to a level that was maintained until day 90 postinfection. An increase in germinative cell frequency was observed at day 90. It is postulated that this increase may reflect a developmental change which has occurred in the cestode following patency.