Dr. D. Bergendal on the Land-Planarice. 47 



exhibit thick cilia, the tuberculiforra basal parts of which 

 give the walls a reticulate appearance. From the longitu- 

 dinal trunks issue straight transverse canals, which may be 

 in part discharging and in part collecting canals. From the 

 conditions found bj Lang in Gunda we should expect a regular 

 arrangement of these ; but hitherto I have been unable to 

 recognize it, although the small number of such transverse 

 canals is decidedly in favour of it. 



The longitudinal trunks are so deeply seated in the paren- 

 chyma that they can scarcely be observed except in sections. 

 The reticular canals and the ciliated funnels, on the other 

 hand, must be studied in the living tissue. In the head we 

 see, both on the dorsal and the ventral side, a great number 

 of canals situated near the surface, which run in curves or 

 reticulately, and sometimes form nearly coil-like loops. In 

 these canals I have frequently seen structures which I must 

 for the present interpret as strong ciliations. They resemble 

 the " flammes vibratiles " which Francotte has described in 

 Derostomum and Monocelis. MetschnikofF also states some- 

 thing of the same kind with regard to the longitudinal canals 

 of Oeodesmus. I cannot regard them as phantasms produced 

 by ciliary movement, because they are only to be seen here 

 and there and because in crushed preparations I believe I have 

 seen in exposed aquiferous vessels very long protoplasmic 

 tongues pointed at both ends. They sometimes appear more 

 membrane-like, and are then attached to the wall of the vessel 

 by one margin. However, they can hardly represent those 

 described by Francotte in Polycelis. 



With the reticular canals the ciliated funnels are connected 

 by very narrow longer or shorter canals, in which usually no 

 phenomena of movement occur. The ciliated funnels are 

 often placed in pits in groups of three or four together, and 

 they present a large rounded excretory cell in which I have 

 repeatedly observed vacuoles which emptied themselves into 

 the funnel. Almost always there are ciliated funnels in the 

 marginal papillae of the head. I hope to be able hereafter to 

 complete these exceedingly troublesome observations. 



The Nervous System and Sense-organs. 



Moseley regarded the nerve-trunks as a " primitive vas- 

 cular system," but nevertheless believed that the nerves tra- 

 verse them. GraflP, von Kennel, Lang, and lijima have shown 

 that they are true nervous cords. In our Bipalium the sections 

 of the nerve-trunks situated beneath the ramifications of the 

 intestine are oval in transverse slices, and show a diiFerence 



