ON A CESTODE FEOM CESTEACION. 405 



rest, and. is to be looked upon ratlier as the beginning of the 

 efferent duct than as part of the ovary proper. It is enclosed 

 in a membrane continuous with that which encloses the 

 lateral portions. The contained, ova, instead of being closely 

 aggregated together, are loosely distributed singly or in 

 groups (figs. 11 and 12). 



The oviduct begins in a well-developed " SAvallowing 

 apparatus" (figs. 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, sic), such 

 as has been described in various other Cestodes. This lies 

 on the ventral side of the isthmus of the ovary and opens 

 into its cavity. It is a bell- shaped structure, the wide mouth 

 of which, directed towards the dorsal surface, opens into the 

 cavity of the isthmus of the ovary, while at the opposite 

 extremity a very much smaller aperture leads into the ovi- 

 duct proper. During life this swallowing apparatus was 

 observed to perforin rhythmical pulsating movements, the 

 effect of which must manifestly be to seize the loose ova of 

 the isthmus, one by one, and to pass them backwards along 

 the oviduct. In sections it is found that the wall of the 

 swallowing apparatus is continuous with the investment of 

 the ovary and w^ith the muscuhir layer of the wall of the 

 oviduct. It has the character of a dense layer of fibres 

 (figs. 13 to 16, sw. VI.), which, though of extreme fineness, 

 must be muscle-fibres. These are for the most part arranged 

 circularly around the wall of the organ, but some are radial. 

 Surrounding this fibrous layer is a single layer of cells 

 (figs. 13 and 14, siv. my.) of irregular shape. Processes pass 

 from these into the fibrous layer, and there can be little 

 doubt that the majority of these cells are the myoblasts of 

 the fibres of the swallowing apparatus. A small number 

 (fig. 13) which give off processes both externally and in- 

 ternally are probably nerve-cells. 



Through the oviducal opening of the swallowing apparatus 

 projects for a short distance a sort of plug perforated by a 

 circular aperture. The substance of this plug is continuous 

 with the epithelium of the oviduct; but, though it contains 

 several nuclei (fig. 16), it does not consist, so far as I have 



