This film discusses the evolutionary significance of segmented worms, particularly earthworms, within the phylum Annelida. It explains the structure and function of their segmented bodies, including ...

This paper describes in some detail the structure of the acrosomal region of the spermatozoon of Hydroides as a basis for subsequent papers which will deal with the structural changes which this ...

This is a preview. Log in through your library . Abstract Each muscle cell of the syllid (Annelida: Polychaeta) proventriculus, the region of the gut posterior to the pharynx, contains a single ...