504 MURIDH—EPIMYS 
of Hossack, and was carried out from a biological and plague point 
of view; he likewise criticises the systematists, but in his paper many 
facts supporting the view that the “varieties” of rattws breed true 
in the country districts will be found; thus rats in large numbers were 
collected from sixty-nine villages in the Punjab, but white - bellied 
specimens were only found in three rather widely separated localities, 
two of them in the Amritsar district, and one in the Lahore district. 
The Egyptian races of vattus have also been studied by Bonhote 
(op. ctt., 1910), who finds only two forms evident there, viz. :— 
(1) &. x. frugivorus,' Rafinesque, with white under parts and light- 
coloured feet, the hind foot being usually 35 mm. long. 
(2) &. r. alexandrinus, Geoffroy, with slate-grey under parts and 
dark feet, the hind foot being usually 33 mm. long. 
Owing to the propinquity of forms, these races are in Egypt very 
much mixed up together, and in practice merely represent extremes of 
a varying series. Bonhote regards these two forms as the analogues 
of the Indian rufescens and grisecventer sub-groups; he finds by 
measurements that a third type, indistinguishable by colour, but with 
a hind foot of 29-30 mm., exists, and he suggests that this corresponds 
to the Indian jalorenszs sub-group, but in Egypt no difference of habit 
is visible. 
A recent examination of the material in the British Museum from 
all parts of the world other than the Oriental region, amounting to 
more than 200 specimens, showed that, adopting Bonhote’s definitions, 
frugivorus could always be distinguished from a/exandrinus ; but some 
difficulty was found in separating the darker specimens of alevandrinus 
from the paler phases of 7. vatéws. Bonhote (1910) showed that when 
the hind foot measurements of a large number of individuals were 
plotted as curves, either for fragzvorus or alexandrinus separately or for 
both races together, the curve in each case showed three apices, viz., at 
35, 33, and 30 mm. In /rugivorus the major apex for both sexes 
occurred at 35; in al/erandrinus it occurred at 33 for males and at 35 
for females ; the minor apex at 30 was regarded as an indication of the 
latent presence of a representative of the Indian jalorenszs group. The 
material in the British Museum similarly treated has given a similar 
result, save that for both sexes of a/exrandrinus the major apex occurs 
at 33 mm. Such facts appear to indicate, according to Bonhote, that 
the three forms are in each case mutations, indestructible and ready 
to develop whenever a suitable environment offers. The curve for 
r. rattus is, however, much more complex, since it shows for both sexes 
large apices at 34 and 36 and a smaller one at 38; for males minor 
apices occur at 30 and 32 mm. 
1 Bonhote uses Savi’s name éecforum for this form ; “ ¢ecforum” is, however, ante- 
dated by Musculus frugivorus, Rafinesque. 
Meteo. 
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