38 Blomfield and Schwartz.—Observations on the Tumours on 
are characterized by their elongated oval shape, and in them fine linin 
fibrils can be seen. From the difficulty with which these fibrils stain it is 
not easy to say what part they play in the process of nuclear division. 
In a given amoeba all these stages take place simultaneously and are 
followed by a considerable increase of its size ; they no doubt take place 
rapidly, as it is only after the examination of a number of sections that 
they are to be found at all. It should be noted that this mode of nuclear 
division takes place within the nuclear membrane. In this way, by the 
multiplication of nuclei, growth and germination take place and the small 
amoebae, as seen in Fig. 2, reach the size and number of those shown in 
Fig- 3 - 
The Chromidial or Akaryote Stage. The next stage in the development 
of the parasite is the disappearance of the nucleus we have described above 
—the ergoplastic or vegetative nucleus—and the appearance of the nucleus 
of reproduction. The organism assumes a more definitely spherical shape 
in place of its former plasmodial appearance, the plasma stains more 
deeply with haematoxylin, the nuclear membrane disappears, and the 
clearly defined karyosome becomes more irregular in shape and smaller in 
size, whilst large granules of chromatin are to be seen at the periphery of 
the nucleus, often arranged at opposite poles. It seems probable that the 
chromatin of the karyosome is conducted to the periphery along the 
achromatic linin filaments. This stage is shown in Figs. 6 and 6 a. The 
continuation of this process results finally in the complete disappearance 
of the karyosome and the chromatin granules, and we get, as is shown in 
Fig. 7, a spherical mass with vague and irregular vacuoles in its plasma, 
which are too badly defined for exact observation. It seems to us 
to be uncertain whether the vacuoles seen at this stage are the remains of 
the vegetative nuclei or whether they are freshly produced in the plasma. 
In the next stage, Figs. 8 and 9, we see collections of chromatin 
granules and rods arranging themselves in these vacuoles into the reticular 
form familiar in the majority of resting nuclei. 
When this is complete there is a separation of the plasma around 
each nucleus, forming what we may term amoebulae, which tend to separate 
but are held together in loose combination by the plasma. This is shown 
in Fig. 10. In the vegetative stage the multiplication of the organism 
takes place in a mechanical way by the separation of portions of 
it during its movements in the cell, but in the reproductive stage the 
relation of the nucleus to its surrounding plasma becomes more intimate, 
and from this time the plasma in immediate relation to the new nucleus 
separates from the plasma of neighbouring nuclei, and though the amoebulae 
are loosely aggregated together there is no longer any resemblance to 
a plasmodium. 
The nuclei of the amoebulae next undergo two divisions, which take 
