52 MR. A. W. BENNETT ON THE 
the primordial germ—a colourless, a blue-green, and a pure 
green. The simplest form of the first—entirely destitute of 
chlorophyll, and adapted to carry on only a saprophytic or 
parasitic existence—is seen in the Bacteria or Schizomycetes. 
To suppose, however, that Bacteria are the most ancient of all 
forms of vegetable life involves an obvious contradiction ; since 
the fact of their being saprophytes presupposes the previous 
existence of living beings of some kind; they must rather have 
been derived by retrogression from organisms of the second or 
‘third class. Be this as it may, from the Schizomycetes are 
probably directly derived the vast group of Funat, the relation- 
ships of which to one another are beyond the scope of the 
present paper. With the highest forms of Fungi this series 
evidently attained its climax. 
'The second type consists of unicellular organisms in which 
the cell-contents are composed of a pale watery blue-green 
endochrome diffused through the protoplasm, without distinct 
chlorophyll-grains, starch-grains, or nucleus—the Chroococcace®, 
represented by such forms as Chroococcus and Glaocystis. 
Although these organisms undoubtedly possess a feebly developed 
power of decomposing the carbonic acid of the atmosphere by 
means of a substance closely allied to chlorophyll, it is still 
doubtful whether they contain true ehlorophyll, and whether the 
first products of assimilation are cellulose, starch, or any of the 
carbohydrates found in the higher plants. Of whatever sub- 
stance their outer membrane or cell-wall is composed, it manifests 
a remarkable disposition to become disorganized into an extremely 
copious coating of gelatin. In Merismopedia we find a tendency 
towards the development of a plate of cells, and in Coelospherium 
towards the botryoid condition which is so much more strongly 
displayed in the Protococcaces. The Chroococcace: have usually 
a slow power of spontaneous motion in the water, but are never 
endowed with cilia. 
The higher forms of the blue-green Protophyta constitute the 
group of Nostochinez, characterized by the filiform condition 
with rudimentary cell-division. The motility of the entire organ- 
ism possessed by the Chroococcacee is now mostly limited to 
special portions of the filament (the hormogones) endowed with a 
reproductive function. Starting from the lowest families of the 
group, the Oscillariacee and Rivulariacee, we may suppose after 
this a bifurcation, in one direction to the Scytonemacee, in which 
