o2. ZOOLOGICAL EXERCISES. 
Pseudogerygone igata. | 
Curruca igata, Quoy et Gaim., Voy. de l'Astrol. Zool. I. p. 20I,. 
pl. 11, f. 2. 
Gerygone flaviventris, Gray, Voy. Ereb. and Terror. Birds, p.5, pl. 4. 
Gerygone aucklandica, Pelz., Reise d. Novara. V6g., p. 65. 
Gerygone assimilis, Buller, Essay on N. Z. Ornith., p. 9. Trans, N. Z.. 
Inst., vol. I. 
Psudogerygone igata, Sharpe, Catalogue of Birds, IV., p. 218. 
This seems to be a very elaborate system, but it is absolutely 
necessary to ensure accuracy. 
Linnzeus, and all who preceded him, attempted to 
arrange animals in one line, but at the commencement of 
the present century Cuvier introduced what is called the 
type system. He ascertained that animals were constructed 
on several different plans, which formed more or less parallel 
lines. He allowed four of these plans, and he called the sub- 
kingdoms thus formed, vertebrata, mollusca, articulata, and 
radiata. In each of these sub-kingdoms, however, a linear 
arrangement was followed. In 1845, Siebold separated the 
protozoa from the radiata, and divided the articulata into. 
arthropoda and vermes. In 1848, Leuckart divided the 
radiata into echinodermata and ccelenterata ; and about the 
same time, Milne-Edwards constructed the sub-kingdom 
molluscoida. There were now eight types or sub-kingdoms. 
In 1860, Darwin showed that community of descent was 
the common bond that linked animals together; and in 
1866, Haeckel showed that the five higher groups must be 
looked upon as diverging descendants, or phyla, from the 
vermes, thus making the first rough sketch of the genea- 
logical tree. 
DIFFERENCES BETWEEN PLANTS AND ANIMALS. 
Fifty years ago, no one thought that any difficulty 
could arise about distinguishing plants from animals, but. 
