184 Life and Immortahty. 
Strange to say, toads and frogs can change to some extent 
the color of their skin to suit their homes. Kept in the 
dark with dark surroundings, toads become darker in color, 
while those that are kept in light with white accessories 
become lighter. The color of the toad changes more slowly 
than that of the frog. It is not the arrangement of the color 
that alters, but merely a change from light to dark. 
What has been said applies to our Common American 
Toad, the Bufo Americana of the books. Let us now look 
at some curious specimens of the Bufonide. The Pipa, or 
Surinam Toad, does not lay her eggs in water, but places 
them on her back. A fold of skin rises up and encloses 
each egg ina separate cell, until the young have not only 
been hatched, but have also passed through all their meta- 
morphoses, and come out fully formed. Another toad, 
abundant in Europe and Asia, is largely colored with bright 
crimson, and the father-toad carries the little ones in sep- 
arate cells fastened to his hind-legs like chains. The young 
change to their perfect shape in these cells, and with the 
withering away of the cells the young toads hop out, able to 
take care of themselves. 
Somewhere I have said that toads are generally silent. 
A little toad about three inches long, called a Natter-jack, 
is common in England, and is a noted singer. His “gluck- 
gluck, gluck-k-k,” can be heard any night. The Green 
Toad, well known on the Continent, is not so noisy as the 
Natter-jack, but has a low, moaning cry. 
All the Tree-toads, or Hylidz, have clear, shrill voices, 
and are fond of singing serenades. In the spring the Com- 
mon Toad takes to the water and there sings very loudly. 
The loud continuous trill that we hear in swamps in spring- 
time is made by toads, and not by frogs, as is generally 
believed. Another toad with a voice is the Spade-foot. This 
Toad is rare, though widely distributed. It is remarkable 
for its feet, formed for digging, its subterranean habits, and 
its queer way of appearing and disappearing very suddenly. 
