South African Lacertilia, Oj^hidia, and Batrachia. 167 
known to occur to-day, and the secretary-bird, which is beUeved to prey 
largely on snakes, seems to include adders in its fare (see Stark and 
Sclater, " Birds of S. Africa "). To us it seems more reasonable to suppose 
that we are here dealing with protective colouration rather than mimicry — 
a supposition which also implies a ruthless destruction of snakes by their 
larger foes. Probably the simplest hypothesis is to regard this simple 
colour pattern as brought about in each case independently in direct 
response to the physical environment and not necessarily in adaptation 
therewith. 
P^RT III.— BATRACHIA. 
Family EANID^. 
Rana fuscigula (D. and B.) ; B.M. Cat., 50. 
Benauwdheid's Font., Jacobsdal (0. F. S. Batten) ; Alexandersfontein, 
Kimberley (A. L. Franceys, J. B. Harrison, J. H. Power), Karreeboom, 
Kimb. (Miss M. Mclntyre) ; Fort Richmond, Herbert (W. H. Wayland) ; 
Victoria West (P. D. Morris) ; Oudtshoorn (J. L. Cairncross) ; Kaaiman's 
River (Miss Wilman) ; Somerset Strand and Kalk Bay (J. H. Power). 
This frog, near Kimberley, lives and breeds in dams where the water 
is frequently renewed, or in running streams : it is never found in muddy 
water. It is usually deep brown in colour, but may be even light green 
with darker spots ; a pale vertebral line is occasionally present. Some 
eggs of this species, attached separately to water-weeds, were found in 
a dam on September 17th ; they were transferred to an aquarium where 
the development was observed until the death of the tadpoles on 
October 15th, when the tadpoles were only 11 mm. long. Development 
seems to be comparatively slow, and most of the tadpoles appear to pass 
the winter as such: they usually reach a large size, a total length of 
110 mm. being not unusual, whilst specimens of much larger proportions 
are occasionally met with. One monster was sent to us by Mr. P. D. 
Morris from Victoria West in May, 1910. The total length is 165 mm., 
the body is as large as that of a moderate-sized frog, the tail is thick and 
muscular, the limbs are well developed and the jaws and oral region are 
typically tadpole-like. In December, 1911, we observed this species in 
a stream near the summit of the mountain at Kalk Bay. Tadpoles 
and young in various stages of development were present, but the 
tadpoles were markedly different from those found at Kimberley, being 
considerably smaller and very fuscous. The total length of the Kalk Bay 
tadpoles was 42 mm. They were evidently undergoing a comparatively 
rapid metamorphosis. 
