102 J. W. JENKINSON. 



iodine adiled to the water in which the creature was living. 

 The iodine material was gradually hardened in alcohol, while 

 that preserved iu picric and chromic acid was transferred to 

 and kept in water containing numerous crystals of naphthalin. 



The stains used were haematein-aramonia and Mayer's 

 hsemalum, the former of which gave the better results. The 

 objects were deeply over-stained, and then decoloured in alum 

 until only the granular portions of the nuclei retained the 

 stain ; they were finally mounted in Canada balsam in the usual 

 way. Only those amcebee were preserved which happened to be 

 migrating into Sphagnum cells ; but their nuclei, and therefore 

 presumably the nuclei of all other amoebae, exhibited the same 

 appearance as those of the cysts. 



In the uninucleate amoebee or cysts the nucleus always 

 occupies a nearly central position, never being situated against 

 the cyst wall, or in the hyaline border of the amoebse. In the 

 multinucleate stages the nuclei are evenly distributed. They 

 may lie in a row if the cyst is compressed by the narrowness of 

 the Sphagnum cell, or, if the cyst is broader, they may 

 alternate with one another in two rows, or in large cysts may 

 lie equally in all directions (Fig. D, 2 — 4), and this uniformity 

 is quite uninterrupted by local thickenings of the cell-wall, or 

 by the protrusions of the cyst. The size of the resting nuclei 

 varies, the diameter being from l^ju to S fi. They are gene- 

 rally round, almost spherical, more seldom lens- shaped, ovoid, 

 or faintly lobed. They lie embedded iu a more or less thick 

 layer of hyaloplasm, which passes indistinguishably into the 

 nuclear membrane. The structure of the nucleus is reticulate, 

 though the threads of the reticulum are so excessively minute 

 that they can only be recognised by the rows of chromatin 

 granules that lie upou them. 



In properly stained preparations the nuclei appear to be 

 divided into layers. In the centre space — about one third of the 

 diameter of the whole nucleus — are generally several, twelve 

 or more, but sometimes only a few, or even one, large, deeply 

 staining granules (Fig. D, 6). These are probably nucleoli; they 

 are not protein crystals, which do not stain with heematoxylin. 



