108 Darwin, and after Darwin. 
The next point we have to observe is, that in all 
cases where a cell or a Protozodn multiplies by 
way of fissiparous division, the process begins in the 
nucleus. If the nucleus divides into two parts, the 
whole cell will eventually divide into two parts, each 
of which retains a portion of the original nucleus, as 
represented in the above figure. If the nucleus divides 
into three, four, or even, as happens in the develop- 
ment of some embryonic tissues, into as many as six 
parts, the cell will subdivide into a corresponding 
number, each retaining a portion of the nucleus. 
Therefore, in all cases of fissiparous division, the 
seat or origin of the process is the nucleus. 
Thus far, then, the phenomena of multiplication are 
identical in all the lowest or unicellular organisms, 
and in the constituent cells of all the higher or multi- 
cellular. And this is the first point which I desire to 
make apparent. For where the object is to prove a 
continuity between the phenomena of growth and 
reproduction, it is of primary importance to show— 
ist, that there is such a continuity in the case of all 
the unicellular organisms, and, 2nd, that there are all 
the above points of resemblance between the multi- 
plication of cells in the unicellular and in the multi- 
cellular organisms, 
It remains to consider the points of difference, and, 
if possible, to show that these do not go to disprove 
the doctrine of continuity which the points of resem- 
blance so forcibly indicate. 
The first point of difference obviously is, that in the 
case of all the multicellular organisms the two or 
more “ daughter-cells,” which are produced by division 
of the “mothcr-cetl,” do not wander away from one 
