ARCHERINA B0LT0N1. 
67 
given off here and there from the mass. In these specimens 
the most striking feature is the entirely altered appearance of 
the chlorophyll-corpuscles. They may he present to the number 
of four, arranged as in fig. 15, and clearly resulting from the 
tetraschistic division of one parent chlorophyll-corpuscle. Or 
they may have proceeded further in the process of fission, each 
one of four having itself divided into four, giving thus a group 
of sixteen, such as is shown in fig. 21. These may retain a 
eery definite and symmetrical arrangement, or the colony may 
have become broken and distorted so as to give such irregular 
grouping as is shown in fig. 20. That there is at one stage or 
other a possible division into two only on the part of the 
chlorophyll- corpuscle of Archerina, is shown by the existence 
of such a group as that drawn in fig. 22, where we have a 
colony consisting of four groups of eight corpuscles. A 
curiously irregular fission is shown in fig. 23. 
The two corpuscles with abundant protoplasm shown in 
fig. 19, are very possibly only a detached “half” of a tetra- 
schistic group. 
It is to be noted with regard to the form of the chlorophyll- 
corpuscles in these groups, that they contrast with the oval and 
irregularly flattened out green bodies of the Actinophryd-phase. 
They are nearly always spherical, rarely ovoid. Occasionally, as 
in fig. 20, each contains a refringent granule, but they are 
usually homogeneous in appearance. The chlorophyll is con- 
fined to a uniform peripheral layer or crust of the corpuscle. 
The spherical form of the corpuscles is apparently connected 
with their active state of growth and division, the breaking up 
of one parent corpuscle into four daughter corpuscles pro- 
ceeding rapidly, and not being delayed in the incomplete state 
of fission seen in the Actinophryd-phase. The protoplasm is 
more abundant relatively in these groups than in the Actino- 
phryd-phase, and is often observed in the act of ingesting solid 
food particles such as Bacteria (seen in fig. 20, i, and fig. 24, *). 
That the multiplication of the corpuscles and the associated 
growth of the protoplasm is very active, seems to be proved by 
the occurrence of such extensive growths of the organism as 
