ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 100.*) 



or merely in a thin hyaline cortical layer. The flagella are either of 

 uniform strength or somewhat conically narrowed. They are usually 

 sharply defined from the body. A steering tail is often present. The 

 flagella readily degenerate, the protoplasm gathers into a terminal 

 vesicle, and the lash is gradually shortened. In the parasitic and 

 marine Flagellates there are no contractile vacuoles. The nucleus 

 was repeatedly observed, and also division longitudinally and 

 transversely. 



New Flagellate.* — Herr J. Krassilstschik describes a new 

 flagellate infusorian which he calls Cercobodo lacininsegerens, which 

 appear to unite the characters of the Cercomonadina with those of the 

 Bodonina ; by its mode of development it shows that it belongs to 

 Biitschli's family of the Rkizornastigina. The creature was found in 

 an infusion of decaying leaves at Odessa. It is small and naked, and 

 has a soft, finely granular protoplasmic body ; no nucleolus could be 

 made out. There were generally coarse, bluish-green or brown, 

 highly refractive granules scattered in the body. When swimming 

 freely the form of the body changes a good deal, the hinder half 

 being especially mobile. In addition to the tail-like cercus there are 

 a varying number of appendages, which are not to be called pseudo- 

 podia, as they are formed passively and not actively. The tail may 

 be withdrawn into the body, which then becomes of a more regular 

 form. Two cilia directed in different directions can be easily seen, 

 and especially the anterior. The creature may pass into a resting 

 stage, when it appears merely as a flat lump of protoplasm, wherein 

 short and broad pseudopodia are extended ; at this period there is no 

 translocation of the body. Cercobodo has no eye-spot (stigma). 



It is quite one of the smallest of the Flagellata, being 11-13 jx 

 long and 4-5 [x broad, 9-10 jj. long and 6 /x broad, or 7 to 8 /x in 

 length and breadth, according to its form at any one moment. It 

 feeds on bacteria of all kinds, and generally feeds when in its free- 

 swimming stage ; food can be taken in at any point of the body, but 

 it seems that the bacteria cannot be digested unless they themselves 

 secrete an enzyma ; when this does not occur the bacterium is allowed 

 to leave the flagellate. During feeding the pulsating vacuole is often 

 increased two or three times in width. 



Neither copulation nor the formation of plasmodia was observed, 

 reproduction being effected only by division, and that during the 

 resting stage ; of this process the author gives a short account. 



With regard to the systematic position of this new form, it belongs 

 to the group Heteromastigoda, and family Bodonina, of which it is 

 the lowest representative ; by its powers of movement, mode of taking 

 food, and great mobility of its hinder end it exhibits affinities to 

 the Cercomonadina ; the mode of reproduction by fission only, and the 

 simple encystation without copulation, ally it to the lowest Rhizo- 

 mastigina. The Monadina, the Euglenoidina, and the Heteromasti- 

 goda, formed a connected group, distinct from the Isomastigoda. 



* Zool. Anzeig., ix. (1886) pp. 364-9, 394-9. 



