THE HOUSE MOUSE 649 
(E. Museo Lundiz, iti, 60; and Danmarks Pattedyr, 90) has drawn 
attention to the fact that in the relatively small House Mice from 
Lagoa Santa, Brazil, me are in course of reduction, being sometimes 
wholly lacking, sometimes wanting from one or the other jaw, and 
when present always smaller than in European examples. Ina skull 
from Cordoba these teeth are absent from both sides of the upper jaw, 
while they are greatly reduced in the mandible. There is thus ample 
evidence of the fact that JZ. musculus is capable of developing new 
forms adapted for leading a wild life amid foreign surroundings and 
among strange competitors. 
DIMENSIONS IN MILLIMETRES :— 





Tail os 
Head and | (without alerene Guntat Weight in 
body. Cee claws). length). grammes. 
SPECIMENS FROM REIGATE, SURREY, CAUGHT AND MEASURED BY L. E. ADAMS. 
SEXUALLY IMMATURE OF BoTH SEXxEs :— 
1. 19th Feb. 1912, average of 7; furred 
above, eyes and ears closed. 44 35 13 55 35 
2. 19th Feb. 1912, average of 4; furred 
above, eyes and ears closed . 45 83 13°5 6 4 
8. 19th Feb. 1912, male; furred above and 
slightly below, eyes vand ears closed . 63 41 14 6 5 
4. 19th Feb. 1912, female; fully furred, 
eyes and ears open 55 64 18 12 7 
5. 28th Aug. 1913, male; fall first pelage 58 62 17 11 8 
6. 17th Dec. 1912, male : 59 59 16 11 7 
7. 80th Dec. 1912, female . 59 60 16 11 10 
8. 29th April 1913, male ; adult pelage 
above, almost adult below . 60 58 17 12 $51 
9, 19th Feb. 1912, female; adult pelage 
above, almost ‘adult below . 64 74 17 13 11 
10, 29th ‘Aug. 1913, male; complete adult 
pelage . 64 68 17 12 9 
11. 2nd May 1913, male; neatly full pelage 65 62 17 12 85 
12. 29th Aug. 1918, male; complete adult 
ge. 6 5 ¢ ° 5 3 65 65 17 11 9 
18. 8th Aug. 1913, male; first pelage below 67 65 16 12°5 10 
14, 9th Aug. 1913, male; complete adult 
pelage . 67 67 16 12 10 
15. 11th Oct. 1911, female; complete adult 
pelage . 68 64 19 13 tS) 
16. Sth Aug. 1913, male; complete adult 
pelage . 68 69 16°5 11°5 12 
17. 31st Aug. 1918, female; not quite adult 
pelage below . 69 64 17 12 9 
18. 13th July 1918, female; ‘complete adult 
pelage . 69 72 16 12 11 
19. Jan. 1912, male; complete adult pel- 
age. 4 c c o > . 69 i7 17 13 10 
20. 15th Feb. 1913, female; complete adult 
pelage . 70 67 15°5 11 13 
21. 29th Aug. 1913, female; adult pelage, 
but imperforate : 70 75 16 12 12 
22. 1st May 1913, female; adult pelage, put 
imperforate’ c . . . 83 78 Ie. 12 15 







1 Nos. 8 and 9 are respectively the minimum and maximum of a series of seven recorded in Adams's 
original table. 
VOL. II. 
to 
Lar 
