13 
constantly in these chai*acters, really represented a 
distinct species. 
The decisive way to test the status of the different 
members of the sciiteUans "roup is by tryinj^ to cross them. 
There are two members in the New Hebrides, scutellaris 
and perjiotatus. W. J. Perry tried crossing these and 
concluded they were distinct species. Scutellaris extends 
through New Guinea to the Philippines. A. H. Woodhill 
ill Sydney tried crossing scutellaris with psendosciitellaris 
from Fiji and found that though they mated successfully, 
the eggs would not hatch, thus confirming that they were 
distinct species. During the war a couple of specimens were 
collected in the Nortlieru Territory that agreed in all 
respects with scutellaris except that they had a white 
stripe along the front of the mid femur, which is all black 
in scuiellaris. Later on Woodhill had some specimens sent 
to him from Katherine and was able to establish a colony 
■and try crossing them with scutellaris from New Guinea. 
TTe found that New Guinea females and Katherine males 
produced fertile hybrids and concluded that if the two 
forms were present in the same area they would interbreed 
and produce a population showing all degrees of inter- 
gradation, and therefore they represented two subspecies 
Aedes scutellaris scutellaris and Aedes scutellaris kather- 
inensis. The cross the other way, Katherine females with 
Ncav Guinea males, produced sterile eggs which showed 
that the two forms had diverged to some extent and Wood- 
hill handed over his colonies to the geneticists for further 
study. Now if a New Guinea and an Australian race were 
to meet somewhere, the logical place would be on Cape 
York Peninsula. All the specimens collected from Torres 
Straits islands appear to be scutellaris scutellaris and so 
does a specimen from near Cape York. But specimens 
collected by J. L. Wassell in the Coen district, though they 
do not have a complete stripe on the midfemur, do have a 
few white scales or a short streak and look very like some of 
WoodhilPs hybrids. Tt is an intriguing problem and these 
specimens can really only be indentified when it is possible 
to establish a colony of the Coen form and try crossing 
it with the other two. 
The examples T have given of some of the varied as- 
pects of taxonomy have all been taken from work on 
insects, for which i make no apology, since that is the field 
T know best. But you can be certain that there are very 
many analagous cases amongst other animals and amongst 
plants. 
Tn Australia we have a general picture of the origins 
of our fauna and flora. Some groups are allied to South 
