92 
ON THE OCCURRENCE OF A SUPPLEMENTARY 
CHROMATIC BODY IN MAUPASELLA NOVA CEPEDE 
(CILIATA ASTOMA), AN INTESTINAL PARASITE OF 
EARTH-WORMS (ALLOLOBOPHOPA CALIGINOSA 
SAVIGNY). 
By D. RERAN, Sc.D. 
(From the Quick Laboratory, University of Cambridge.) 
(With Plate VI.) 
Maupasella nova Cepede was discovered by Maupas (1877) in the alimentary 
canal of an Algerian earth-worm and subsequently described by Cepede (1910). 
As was well remarked by the latter author, this ciliate varies much in size 
and in form, long specimens measuring 80-95 by 25/x, and short ones only 
50-75 by 27-47/x. The essential characters of Maupasella are: (1) the presence 
of an anterior fixing apparatus in the form of a conical process derived from 
thickened ectoplasm, (2) an elongated ribbon-like macronucleus, (3) irregu¬ 
larly disposed contractile vacuoles, and (4) dense ciliation. Moreover, the 
micronucleus (PI. VI, fig. 18 and m in all the other figures), which is often 
difficult to see, is spindle-shaped, with its axis parallel to that of the ciliate’s 
body, strangulated in the middle and with the chromatin condensed into a 
disc lying in the strangulated portion of the spindle. 
In many specimens of M. nova obtained from the alimentary canal of 
Allolobojihora caliginosa Sav. collected near Paris (France), I found a ribbon¬ 
like supplementary chromatic body which I propose to describe here. These 
bodies occur in specimens of Maupasella which are of different size and form. 
They stain deeply and uniformly with basic stains, especially with iron- 
hematoxylin, and never show the granulated structure which is so character¬ 
istic of the macronucleus. Their ^position in the endoplasm of the ciliate, as 
well as their shape, varies very much (PI. VI, figs. 1-17); in some specimens 
of Maupasella the chromatic body is straight and parallel to the macronucleus, 
while in others it is curved in the form of an S or C, or is strangulated in the 
middle and having one end twisted round the macronucleus (PI. VI, figs. 9, 10 
and 12), but in no case has any continuity between the latter and the chromatic 
body been observed. I nvery elongated examples of Maupasella, which are 
going to divide (PL VI, figs. 9 and 10), and in already dividing specimens 
