320 M. N. Lieberkuhn on the Anatomy of the Infusoria. 



which he rcgarilocl as indicative of the commencement of 

 division. 



The animalcule took up abundance of indigo. I did not see 

 any excretion of substances, and hence I cannot state anything 

 about an anal j)oint ; no special orifice was visible. 



The presence of an eye-spot, the j)osition of the mouth, the 

 complete investment of the body with cilia, require the assign- 

 ment of the animalcule to the Ophrijorjleno' ; and the described 

 form of its body, its colour, the peculiar pouch-like form of the 

 mouth, the variability of the distinctness of the pigment-spot, — 

 all these make it appear warrantable to name the animalcule 

 Ophrijoylcna jlavicans, until more certain distinctive characters 

 have been discovered. The following notices regarding it relate 

 more particularly to the existence of a hitherto unobserved 

 watch-glass-like organ near the pigment-spot, and to the vascular 

 system. 



The Eye-spot and the watch-glass-like Organ. 



In order to describe accurately the position of these organs, 

 it is necessary previously to give a more particular account of 

 the mouth of the animalcule. The mouth forms a narrow slit 

 in the form of a semicircular line, and lies in a small depression. 

 In a large specimen, measuring 7*\jths of a millimetre in length 

 and j^^ths of a millimetre in breadth, the distance of the upper 

 point of the mouth from the end of the head was jo^^ ^^ ^ 

 millimetre, of the lower from the upper point of the mouth 

 y§^ijths of a millimetre. The oral cilia, placed all round the 

 margin of the slit, are far longer than the cilia of the rest of the 

 body, although these are also remarkable for length; the cilia 

 of the mouth are seen to project far beyond the others when 

 the animalcule lies so that the mouth is on the outline of its 

 figure. The oral slit leads directly into a sac-like space, which 

 may be traced for a short distance into the cavity of the body, 

 whenever the latter is not filled up with the strongly refractive 

 granules ; we may also then detect a membi'ane constantly 

 vibrating backwards and forwards in the interior of the sac. 

 But this part ordinarily only becomes distinctly visible when 

 the oral portion, with the pouch, has been isolated by the com- 

 pression of the animalcule; the mouth is the entry into the 

 pouch ; at the opposite side is an orifice, through which sub- 

 stances which have been taken in by the mouth are conducted 

 further. Near to this is attached the vibrating membrane, and 

 it is fixed by one angle to the internal wall of the sac, while the 

 other parts project freely into the cavity of the latter. That it 

 is not merely an apparently undulating membrane, as Stein 

 correctly asserted of the ciliary wreath of the Trichodina, is at 



