34 : J. B. CLELAND. 
y 
elsewhere. A ceaseless vigil has been kept upon them here, ° 
and daily examinations are made for the purpose of antici- 
pating any future recurrence of plague in human beings. 
Consequently a large amount of data has been collected in 
my laboratory in connection with them and their habits, 
parasites and diseases in general. 
Though in such a systematic survey of rats, the common 
house mouse, Mus musculus, is included, being also subject 
to plague, much general attention had not been directed io 
this small pest till recently, when the enormous havoc 
amongst our wheat stacks caused by its phenomenal abun- 
dance perforce directed attention to it. 
With this short introduction, the consideration of our 
rats and mice divides itself naturally under the following 
headings — 
The Species of Rodents concerned, and their Habits. 
The Damage done by Rats and Mice. 
The Distribution and Prevalence of the Common Rats 
and Mice in Australia. 
The Numbers of Rats and Mice per Litter. 
The Rats that Travel by Sea. 
The Diseases of Rats: 
Community Animals and the Origin and Spread of 
Epizootie Diesease. The True Significance of Disease. 
The Manifestations of Disease may be Specific. 
Attributes both of the Parasite and of the Host. 
Plague: The Romance of Plague. A summary of the 
occurrence of Cases of Plague in Australia. The 
Species of Animals naturally infected with Plague 
in Australia. 
Rat Leprosy. Spirochetosis ictero-hemorrhagica. 
Rat-bite Fever. 
