14 



ART. 4. — EKITArtO NOMURA.: 







Fig. 6. 



L. gotoi. Longitudinal section of a septal sac through about its middle, x 700. s— septum, 

 TT — Tentral Tessel, chl — chloragogue cell. 



The septal sacs, which are outgrowths of the septa, are 

 attached in pairs to the posterior faces of septa V/VI-IX/X, on 

 the ventral side of the intestine. The sac is provided with a 

 thin structureless membrane, and always contains many club- 

 shaped cells, between which certain interesting relations can be 

 made out. The cells, which are seen at the entrance of the sac, 

 are undoubtedly chloragogues, while those at the bottom are 

 smaller and have a dense cytoplasm ; and between these two 

 forms there are cells of intermediate characters. Confining our 

 attention for the present to the septal sacs, the conclusion is 

 justified that one sort of these cells is derived from the other, 

 and as to the relation of these cells to the chloragogues, there 

 are two possibilities : either that the chloragogues change into 

 the bottom cells, or the reverse is true. At present I have not 

 sufficient data to decide between these two alternatives ; but one 

 fact appears to me clear, that the septal organs have an intimate 

 relation to the ventral blood vessel passing through them. Each 

 bottom cell always contains a single nucleus, which is somewhat 

 elongated and rarely nucleolated ; the presence of a cell wall is 

 very doubtful. 



Before leaving the septal sacs I must make one or two 

 remarks on the septal glands described by Hatai. He says, 



