116 



NATURAL HISTORY OF BIRDS. 



from that common stock of which we here see the more or less direct descendants, 

 will not be ascertained before the embryology of all these forms shall be known, and 

 perhaps not even then. Nor may we expect much from future palasontological 

 discoveries ; here and there a find may throw some light upon affinities and the history 

 of development, but "the gaps are great and many. We will therefore, for the present 

 at least, have to content ourselves with such reasonable probabilities as can be derived 

 from the comparative anatomy and the geographical distribution. 



The sun-bitterns, family EURYPYGID^E, genus Eurypyga, as already indicated, are 

 South American birds of a rather peculiar appearance, something between a rail and 



FIG. 55. Eurypyga helias, sun-bird, sun-bittern. 



a heron, though the long tail, the ample, broad wings, and the peculiar coloration at 

 first glance distinguishes them from both. Referring to the cut for further details 

 of external structure and for the general aspect, we need only mention in regard to col- 

 oration that the sun-bird, as it is also called, is beautifully variegated with white, brown, 

 and black bands and mottlings, the head being black with white marks. The eye is 

 red, bill and feet yellow. The feathers are soft, and the shafts of those on the back 

 and rump are extremely fine and delicate in the centre, which causes the tips of each 

 feather to turn the reverse way directly the bird is dead. Another remarkable fea- 

 ture is the extremely thin neck. The sun-bitterns inhabit the banks of the great 



