130 J. J. LISTER. 



another in the canal, and, in the chamber beyond, to be disposed 

 concentrically around the aperture by which the protoplasm 

 has entered (fig. 1). These protrusions are frequently repeated 

 through successive chambers. 



The movement of the protoplasm to which this effect is due 

 occurred, no doubt, solely as the result of the action of the 

 reagent used in killing it. 



In many cases the nucleus is involved in one of these 

 movements of the protoplasm, a portion of it being carried 

 through into the succeeding chamber, where it is seen drawn 

 out, and, like the protoplasm which surrounds it, disposed 

 concentrically to the aperture by which it entered. Portions 

 may thus be carried through as many as three chambers from 

 that in which the main body of the nucleus lies (fig. 1). 



Bodies other than the Nuclei contained in the Protoplasm. — ■ 

 In Polystomellas collected in summer there are present in 

 about one specimen in five or six of the megalospheric form, 

 and also in specimens of the microspheric form, small bodies 

 of a rounded shape, which take a red stain with picro-carmine 

 (fig. 2). They are most abundant in the terminal chambers, 

 becoming fewer and fewer as the series of chambers is fol- 

 lowed backwards. In some cases they also increase in size 

 towards the terminal chambers. The size may vary from 8 ft, 

 in diameter to 1 /i and under, and in any specimen, though 

 frequently uniform, they may present considerable variations in 

 size. Sometimes they are so abundant as to form a prominent 

 feature in a stained specimen (fig. 2) ; in other cases they are 

 sparsely scattered through the protoplasm, and, as stated above, 

 they are absent altogether in the majority of specimens. These 

 statements hold true of examples killed and stained in a batch, 

 so that the differences cannot be dependent on different modes 

 of treatment. 



Though generally spherical, they sometimes present an 

 elongated shape, and they may be excavated by deep concave 

 indentations (fig. 3), which may be so extensive as to reduce 

 the body to a hollow shell of stained material. 



While they are generally uniformly stained, in some case§ 



