KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:O |7. 95 
generally characterizes the nests of the small birds in the savanna-woods of North- 
West Australia. Here this relation between reptiles -and birds seems to have reached 
considerably greater proportions than is the case in other countries or provinces, or 
perhaps it is a more strongly conspicuous feature because of the low and thin species 
of bushes and trees. 
It may be considered as self-evident that this form of nest-building is a develop- 
ment from a simpler form, where probably the more primitive way of building that 
Fig. 9. Nest of Pitilotis fasciata from Sunday Island. 
in some degree still characterizes many more of the representatives of the Passeri- 
formes in our North than corresponding forms in Australia requires as a necessity 
basement, on which the nest first may have been build. The transporting of the 
nest from, for instance the upper surface of a branche, out to the flexible twigs in the 
most peripheric parts of the foliage has caused a new manner of nest-building. Here 
the beginning of the nest is not made in the form of a base but is begun by con- 
structing the circular part that goes to form the edge of the nest. 
The development of this structure has also required a building-material, which 
has facilitated that rather clever joining together, which characterizes this method of 
K. Sv. Vet. Akad. Handl. Band 52. N:o 17. 4 
