FLAGELLATE INFUSORIA AND ALLIED ORaANISMS. 67 



is no doubt that Spumella truncata takes solid food, although 

 neither the kind of nutriment nor the mode of ingestion is 

 yet ascertained, owing to the rapid and uninterrupted move- 

 ments of the organism. 



Chromulina Cienkowski (" Ueber Palmellaceen und 

 einige Flagellaten," * Archiv. fiir Mikr. Anat.,' Bd. vi, 1871, 

 p. 435). 



Small Elagellata with a flagellum, contractile vacuole, and 

 coloured disc. Inside is a cyst — the entocyst. No solid 

 food appears to be taken. The presence of the nucleus is 

 doubtful. 



Chromulina ochracea, Ehrenberg ('Die Infusionsthiere 

 als Vollkommene organismen,' Leipzig, 1838, p. II, pi. i, 

 fig. 7), Monas ochracea, Ehrb. — These small organisms are 

 placed in the genus Chromulina, Cienk., in spite of the fact 

 that the production of a cyst within the protoplasmic body — 

 which is the most remarkable peculiarity of the species — 

 has not yet been observed. The identity with Monas 

 ochracea of Ehrenberg is very doubtful. 



Chromulina ochracea (Plate vi, fig. 4) is a small organism 

 measuring 0006 to 0*008 mm. in length and breadth ; it was 

 obtained in the lake in the Grand-ducal park at Carlsruhe, 

 where it was present in such numbers as to tinge the water 

 of a yellowish-brown colour. The body is much flattened 

 (fig. 4 c, seen from the narrow side), being heart-shaped, oval, 

 or sometimes irregular in appearance, when looked at from the 

 flat side (fig. 4 a b). Within the colourless protoplasm 

 composing the body, two large coloured discs of a brown or 

 yellowish-brown colour are constantly present ; these discs 

 entirely fill up the interior of the body. In the narrower end 

 of the body lies a deep red eyespot of elongated rod-like 

 appearance, and close to it are usually a number of dark 

 granules of high refractive index (fig. 4 a and b). About the 

 centre of the body is a contractile vacuole, which is very 

 conspicuous during the diastole, and which contracts tolerably 

 slowly. The very rapid flickering, as well as convulsive and 

 tottering movement, which is only broken at intervals by short 

 periods of rest, is due to a flagellum of two or three times the 

 length of the body, which is very difficult to observe. It 

 probably arises, not from one end of the body, but from one 

 of the broad surfaces of the body (fig. 4 c) . No nucleus has 

 yet been noticed. Occasionally some of the organisms which 

 seem to have lost their flagellum, execute amoeboid move- 

 ments and put out tolerably long pseudopodia. 



