118 
POPULAR SCIENCE REYIEW. 
broad side of thread of mercury instead of the narrow side, as in the ordi- 
nary thermometer. The advantage being that the external temperature may 
be more easily read off than in the ordinary instrument. 
ZOOLOGY AND COMPAEATWE ANATOMY. 
The Domestic Cat. — In an article, as remarkable for its classical erudition 
as for its scientific importance. Professor Eolleston asks and answers 
the question — Are modern cats of the same species as the cats of the 
ancients? He concludes that the domestic cat of classical times was 
probably the Marten, one of the Mustela group, while, of com-se, he admits 
that our modern cats are genuine Felides. The evidence adduced in his 
extremely interesting paper goes to show that, in the classical period, the 
word ya\i) was used by the Greeks to denote the Musteline Martes and 
Ferret, but not the Polecat probably, though probably the Genet ; and 
that in later times, but not till later times, it was used also for the Felis 
domedieus. The word mustela does not seem to have been transferred 
together with the office, when the latter was handed over from the Marten 
to the Felis, in Italy. In the East the Felis took both the name and the 
work of the rival it supplanted. It did succeed in supplanting the Marten 
as the domestic mouse-killer, probably partly by virtue of its greater at- 
tachment to man and to place, partly by virtue of its less pronounced 
tendency to burglary and petty larceny, partly by virtue of its more even 
temper, and partly by its greater cleanliness and less offensiveness. The 
very points, also, in which as a wild animal it is inferior, make it superior 
as a domestic one to a musteline. Its constitution being less plastic it 
cannot fit itself as easily as they can to varying climates, and in many, as 
Rengger has shown of Paraguay, it cannot run wild. Its range of foods is 
more limited, and its faculty for, and its courage in adopting, new methods 
of purveying for itself, less conspicuous than theirs. Hence “ the poor cat 
of the adage ” being more dependent on man, has been obliged to render 
itself more useful to him than the Marten, and it has very successfully 
turned its inferiority to ‘^commodity.” — Vide Journal of Anatomy and 
Physiology, November. 
Parthenogenesis in Psyche helix . — Herr C. Claus, of Marburg, has published 
a paper, of which an abstract appears in the last Microscopical Journal, to 
prove that the male of Psyche helix exists, and that therefore it is not un- 
likely that parthenogenesis does not occur in this genus. Our readers are 
aware that the case of P. helix was one of the leading cases ” in the 
history of Parthenogenesis. 
The Development of Insects. — The period at which indications of the sex 
present themselves in the insect embryo is at present a point pretty sharply 
debated. Herr Landois, whose curious experiments on the eggs of bees we 
some time since referred to, concludes that the sexual distinctive characters 
are not present till after the embryo leaves it. This view of the develop- 
ment is seriously questioned by Von Siebold and others, who adduce 
numerous instances in opposition to Herr Landois’ opinion. — Vide Zeitsch. 
fur Wissen Zool, vol. xvii. part 3. 
Effect of Chemical Substances on Infusoria . — The experiments which have 
