HORNS IN BIRDS 
head shows a pair of elevations of the bone which suggest 
exactly the bony horn basis in certain mammals. It 
seems to us very probable that if nothing were known 
concerning this crane save its skull-cap, it would have 
gone down to posterity as a horned bird. And very | 
likely the tiny horn on the head of the horned screamer 
(Palamedea cornuta), a close ally of the screamer Chauna, 
as we note on another page, would have been quoted as 
the last vestige in a living bird of a former horned race. 
But the crane is not horned, only crested. The deep 
note of cranes, of intense loudness, is familiar to all 
visitors to the Zoo, and is especially to be heard at evening. 
It is aided by the long windpipe, which is coiled like a 
trumpet and adds of course by this increase of length 
to the volume of the sound produced. This special 
arrangement is not found in our crowned cranes, who 
are thus less specialized and more primitive representa- 
tives of the crane tribe than the remaining forms. 
THE SCREAMER 
South America is the home of many waning races 
of birds and beasts ; in its dense forests there lurk repre- 
sentatives of whole groups, which once flourished abun- 
dantly upon the the land, but are now reduced to scarce 
waifs and strays, the flotsam and jetsam of a previous 
order of things. There is one living “ diprotodont ”’ 
marsupial, the sole remnant of the otherwise extinct 
family Epanorthide ; the rail-like Heliornis or Podoa 
forms, with two allies in Africa and the East, the sole 
remains of a group of birds possibly antecedent to the 
widely spread rails and water hens of the rest of the 
world; the mysterious Guacharo or oil-bird is of a type 
peculiar to itself at present, and the “ Four-footed ” 
bird of the northern parts of the South American con- 
tinent (Opisthocomus cristatus) has not a single close ally 
living anywhere else. Among this wreckage are to be 
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