230 MISCELLANEOUS NOTES. 
No. III.—On the Breeding of the toad ufo macrotis. 
In northern Siam the breeding season of this toad occurs in late 
July and early August, when the skin of the male becomes smocth, and 
changes from dark brown to quite a bright yellow colour, the female 
retaining her normal characteristics. They are to be found in large 
numbers in pools in or near small forest streams, the males invariably 
preponderating. Three or four males may be seen paying very forcible 
attention to one female. This year when with Mr. R, J. Chaldecott, we 
founda dead female with both forearms torn off and a large open wound 
on the beliy, and yet there were still three males attached to her. In 
the same pond there were numerous other groups, consisting of several 
males with but one female, and the noise they made could be heard a long 
way off. I at first thought that the bright colouring must as suredly 
attract the attention of their natural enemies, but when approached they 
all become silent and looked extraordinarily like dead leaves floating on 
the water. Ifthe males are separated from the females they very soon 
resume their normal colouring, but although I kept them for several 
days, their skin did not become warty, as it is out of the breeding 
season. 
From the above facts [came to the following conclusions :— 
Firstly, that the colouring of the males is assumed originally as a 
sexual attraction, and secondly, as the males, when disturbed, make no 
attempt to escape, they use this colouring as a form of defensive 
mimicry. 
The only other case that I have come across of a batrachian 
changing colour is that of Microhyla berdmorii, in which the red tinge 
of the male becomes rather more intense during the breeding season. 
As to the passionate wooing of tha males of B. macrotis, Darwin, in 
his ‘* Descent of Man,” states that Dr. Giinther had ‘‘ several times ” 
found an unfortunate female toad dead and smothered from “having 
been so closely embraced by three or four males.” 
It would be interesting to know if similar instances have been 
observed in other species during their breeding season. 
P, A. R. Barros. 
November 1918, 
JOURN, NAT. HIST. SOC, SIAM, 
