34 A. OKA. 



(Hartii. Imin. lO) wai.' es iiiclit moglich das liintero unci vordere Elide genau 

 ZLi verfolgen. Doch schien mir das Hinterende init einer schwachen Erwei- 

 terung in die Leibesliolile zu mtinden, das vordere Ende aber irnt den 

 dunkelkornigen di-nsenabnliclien Mesodermzellen in Verbindung zu steben, 

 die zain Tbeil wenigstens eine reiben weise Anordnung zeigen und in 

 welcben icb njebr mals einen Canal zu verfolgen glaubte ; docb sind mir 

 diese Yerbaltnisse sebu zweifelhaft geblieben." Jobet, wbo investigated this 

 organ in Ped/celUiia and Loxosoma came to more satisfactory results. To 

 quote bis own words, " Coux-ci (tbe vibratile organs) sont deux canaux assez 

 courts, attenuus vers I'extreraite, renfles au milieu, formes, d'apres Hatschek, 

 de cellules perforees, mais on je n'ai pu distingner, avec des grossissements 

 superieurs a ceux employes par cet auteur, qu'une obscure division trans- 

 versale, sans qu'il m'ait ete possible do constater une structure cellulaire 

 bien nette. Le pavilion (pii termine cba(|ue canal ressemble a un entonnoir 

 taille en bee de fiute, fenda sur la ligne mediane sur un certain longueur et 

 dont de bord bbre serait epaissi en bourrelet sur une certaine etendue et se 

 prolongerait plus loin en une levre delicate." As to tbe pbysiological role of 

 tbis organ, tbe autbor does not give anything deiinite, be only denies tbeir 

 service as evacuatory canals for tbe genital products. Tbe following remark, 

 wbicli be makes on tbis organ, migbt be of much weight in tbe consideration 

 of its function : " Les parois de ces cananx sont si minces, qu'elles ne 

 peuvent guere etre regardees comme glandulaires et formant un organ 

 excreteur." 



Comparing the organ descriljed by Joliet, with the one I have treated of 

 in tbis paper, we find tbe following points of agreement. J. They are both 

 composed of two short ciliated tubes, opening at one end into the body-cavity 

 and at the other into the surrounding medium. 2. They are both situated 

 between tbe mouth and tbe anus in the vicinity of the nervous ganglion 

 3. They are both destitute of a glandular portion, so that they can not be 

 looked upon as an excretory organ in itself. They can only serve as a 

 passage for substances contained in the perigastric fluid. From these con- 

 siderations, it seems highly probable that in both forms tbe excretory fanc- 

 tion is carried on in the same manner, that is, the leucocytes absorbing ex- 



