CLASSIFICATION. 35 
a class, the Monera or Homogenea, regarded by him 
as occupying a lower plane in the evolution or differ- 
entiation of structure. Others, notably Biitschh, con- 
sidered a merely negative distinction valueless, and 
subsequent investigation has confirmed their judgment. 
The presence of nuclei or nuclear substance, in some 
form, has been demonstrated in many species where 
formerly it was not suspected. Assuming Biitschli’s 
dictum to be well grounded, that “the nucleus needs 
the plasm and the plasm the nucleus,” in the develop- 
ment of a perfect organism—that the activities of 
both are reciprocal, and one without the other cannot 
live, a conclusion strongly deducible from all that has 
been ascertained regarding their vital functions— 
Haeckel’s separation of the apparently non-nucleated 
forms from the general group seems unwarranted, 
and his term “Monera,” and also “ Homogenea,” 
should disappear. 
Professor Lankester describes the substitution, in 
his genus Archerina, of a chlorophyl-coloured capsule 
for the nucleus proper,—it is representative, in fact, of 
the nucleus,—and whilst refraining from the assertion 
that no existing Protozoa are devoid of nucleus, corre- 
sponding in this character with the non-nucleated 
Protophyta (e.g. Bacteria), he found the inclusion, in 
his proposed system of classification, of the Homo- 
genea, impracticable, and chose to defer taking that 
step until it had been conclusively shown that forms 
now regarded by some as homogeneous (Biomyea, 
Gymnophrys, etc.) are really so. The general relations 
of these apparently non-nucleated forms with the 
nucleated most nearly allied to them cannot be ignored 
in any systematic arrangement. And, it may be 
added, in any case the form of the nucleus, when 
present, is of little specific value. 
The arrangement here adopted is, in its main 
features, on the lines now most generally accepted by 
Continental authors, whose long-sustained and fruitful 
investigations entitle them to respect. 
