Ylhratih Twjs or FUnnc Cell In Rotifem. 133 



flame cells he has examined are of similar structure Vallentin' 

 gives a figure of the flame cell of Brachiotius rubens obtained by 

 the section method showing a thin wall with a broad flagellum 

 hanging from the cap. 



In the face of these statements by observers of such eminence 

 I advance my views with diflidence. However, as repeated 

 examination of many individuals of B. pala and E dilatata and 

 observations of a less number of each of the other species flgured, 

 as well as others not figured, such as Anurea sp., Synchieta 

 peciinata, Notops brachio?ius, and Pterodina patina all combine to 

 corroborate the view I take, the record of these oVjservations may 

 be of service. 



With the exception of Dr. Weber, none of the observers 

 mentioned appear to have noted the sti'iated nature of the 

 walls of the tag. This he regards as due to a tine muscular 

 network. I suggest that the conclusion as to the undulatory 

 body being a number of waving cilia has arisen through 

 these striations being perceived through the undulating mem- 

 brane, and being confused with it. Indeed at first sight it 

 seems obvious that cilia are present. I have already men- 

 tioned how flame cells of reduced activity show distinctly 

 that the striation is on the walls and further that the undulating 

 membrane is very transparent, in fact it can only be distinguished 

 in the flat aspect by the interference with the light due to its 

 movement. In. dead animals it cannot be seen in the flat. 

 Vallentin's figure above nientioned appears in the light of my 

 observations as a longitudinal section taken somewhat obliquely. 

 Without dealing separately with all the views quoted I suggest 

 that they are all possibly due to the differing appreciations of 

 this combination of an undulatory hyaline membrane and two 

 striated walls which themselves in the living animal are in 

 constant movement. Mr. Rousselet's views are of course excepted, 

 and I regret being unable to procure a copy of his paper, more 

 particularly as I have fortunately met with Asplanchna amphora 

 and find the structure to coincide with the description so far as it 

 is given by Zelinka. I have in vain endeavoured to procure a 

 copy of this paper and of course am unaware as to how far my 



1 Ann. and Mag. of Nat. Hist. Ser. 6, vol. viii., p. 44. 



