THE OPALINID CILIATE INFUSORIANS. 



55 



The number of macrochromosomes is four. 



Protoopalina montana is a little broader in the posterior third of 

 the body than is the usual P. hdeslinali^ and is more broadly rounded 

 at the posterior extremity. It is a much smaller species, if we may 

 judge from the one infection studied. The nuclei are relatively 

 larger, are pear-shaped and connected by a thread, and usually each 



a b 



Pig. 30. — Protoopalina Montana, X 460 diameters. 



will be found in a late anaphase condition, each daughter nucleus 

 simulating an equatorial plate. Out of fifty-two individuals observed 

 on one slide, forty-four showed the nuclei in this condition; six had 

 the two nuclei farther apart, but still connected by a thread, and each 

 showing either eight irregularly arranged chromosome masses or 

 eight massiA'e chromosomes in two early anaphase groups of four 

 each ; one had its nucleus in a very much elongated and greatly con- 

 stricted dumbbell condition, with four massive chromosomes in each 

 of the developing daughter nuclei (fig. 30, a). The two daughter 

 moieties were so far apart that one could almost as well call them 

 distinct nuclei connected by a thread, the thread in this case, how- 



