BIRD-NOTES 59 



greatest authority on bird-anatomy, places it amongst 

 the Shrikes, in the Family Gymnathidce. 1 



The nesting habits of the Hornbills are very remark- 

 able, and though they have been studied by more 

 than one naturalist, there is much that still remains 

 to be discovered. The nest is always built in a 

 hollow tree, and it is essential that the cavity should 

 communicate with the exterior by means of a slit or 

 hole. Very often the hollows in trees are the result 

 of the ravages of Termites, and it is no uncommon 

 thing to find a Hornbill's nest built on the top of a 

 Termites' nest. If the slit, whereby the hollow com- 

 municates with the outer world, is not at exactly the 

 right elevation and this must happen very often 

 the hollow has to be filled up from the bottom with 

 sticks and other vegetable detritus until the pile reaches 

 such a height that the hen-bird when sitting on it 

 can thrust her bill through the slit. On the top of 

 the pile of decayed wood and sticks is a thin stratum 

 of feathers, evidently plucked from her own body by 

 the hen-bird. 



The next stage in the building process is the wall- 

 ing-up of the hen-bird by the male. The sides of the 

 orifice leading into the hollow of the tree are plastered 

 with a peculiar substance, apparently secreted by the 

 bird, until merely a long and very narrow slit is left, 

 up and down which the beak of the imprisoned female 

 can move. I have examined some of the material used 

 by Bnceros rhinoceros to seal up the opening to the 

 nest ; it was quite hard, but rather friable on the sur- 

 face, and was made up of woody particles in a matrix 



1 See Dr. Hose's note on this species in The Ibis (6 Ser.),V. (1893), 

 PP. 393-94--E, B. P. 



