William H. Coil

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The embryogenesis of the tapewormCittotaenia variabilis from the oocyte to the oncosphere is followed using scanning electron microscopy (SEM) in conjunction with ethanol cryofracture. Transmission electron micrographs and histochemistry are used to corroborate the inferences drawn from the SEM studies. Evidence is given for oocyte granules, the uterine(More)
Snails of the species Fossaria bulimoides were exposed to miracidia of Fascioloides magna for given periods of time. The course of penetration was followed by means of scanning electron microscopy. Topographical features of the miracidial morphology were studied; the apical organ, epidermal plates and their shedding, and body shapes during penetration.(More)
The penetration of the miracidium ofFascioloides magna into the snail hostFossaria bulimoides is followed by examining the process at certain, timed intervals during the course of penetration. The cilia are lost early, but the epithelial cells may detach or they may be carried into the snail body. The apical gland releases vesicles which lose their outer(More)
Scanning electron micrographs (SEM) are shown of the scolex, microtrichs, and the submucosal capsule formed by the worm. The course of development of the outer capsule and the outer envelope from the early preoncosphere to the mature oncosphere is followed by SEM and (in part) transmission electron microscopy. Three phases of development of the outer(More)
The constituent parts of the oogenotop are described using certain histochemical tests. Early egg formation and the contribution of the various parts of the female system are followed. The development of the oncosphere and its membranes is discussed. Sperm formation and insemination are described. Untersuchung der Biologie des Bandwurms Dioecocestus(More)
The formation and histochemistry of the egg membranes is followed. Evidence from electron micrographs is presented. A unique kind of hatching is recorded for this species. An attempt was made to quantitate the reduction in size associated with the growth and maturation of the oncosphere. Many questions remain to be answered concerning the development of(More)
STEPHENS (1911) described a new pronocephal id (Desmogonius desmogonius) f rom the Nicaraguan tur t le (Chelone mydas). The specimens were killed and preserved in salt and the original descript ion was based on informat ion taken f rom a single specimen. I n view of these facts, i t is deemed advisable to redescribe this t r ema tode uti l izing informat(More)