president’s address. 
659 
a variety of micro-organisms in the jelly — which is, 
consequently, not of animal origin.” I next forwarded 
a sample to Mr. Balfour Browne whilst he was at the Sutton 
Laboratory, and he replied as follows : “ I have occasionally 
found similar masses, and like you. have associated them 
with Frogs, believing — though without any good grounds — 
that they are the result of some disease in the reproductive 
organs of the females. These masses of jelly have not, so 
far as I have been able to find, any structure, and I dare say 
you have noticed that they have a ‘ froggy ’ smell. They 
are usually the haunt of large numbers of infusorians and 
unicellular algse.” 
My own idea is that it is the imperfectly developed spawn 
left by Rats, or squeezed out by Herons, whilst feeding on 
hibernated Frogs. Fully developed Frog’s spawn swells 
greatly in water after being naturally deposited, and the 
absorption of moisture may well account for the masses 
previously mentioned being sometimes as large as Ducks’ eggs. 
On January 23rd. 1903, I found several pieces on the ice 
covering of a marsh ditch ; there were Heron’s footprints on 
the snow around, but no mark of Rats’ work. I may here 
say that the idea is prevalent amongst marshmen that Frogs 
“ gum up their mouths in the winter time, and if you then 
force open their lips, they will die directly.” 
A curious fact in connection with the life history of the 
Frog, is the fact that their singing generally takes place after, 
and not, as is the case with birds, at or before the breeding 
season. For instance, in 1907 I found Frog spawn during 
the third week in March, but did not hear their croaking 
chorus until the second week in May. This music — which is 
sometimes continued into July — has given Frogs the local 
name of “ March birds ” ; this may be a corruption of “ Marsh 
birds.” at any rate, the latter is the more appropriate, for it 
is very seldom indeed that Frogs or loads are heard to croak 
hereabouts in the month of March, although Gilbert White 
VOL. VIII. 
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