12 THE AUSTRALIAN NATURALIST. 
remarkable difference in both ovary and fruit. It is a re- 
markable flower and well worth cultivating. I have seedlings 
received from Greenough Flats, W.A. E. J. BICKFURD. 
Thynnus variabilis.—V ery little is known about the life- 
history of these curious flower wasps. The wingless females 
have short stout legs adapted for digging. Like the Scolid 
wasps, they apparently burrow into the loose soil and deposit 
their eggs upon the grubs of the large brown cockchafer 
beetles. The cocoon of Thynnus differs from that of the 
Scoliidae in having a rounded nipple at one end. Australia 
is the home of these handsome flower wasps. The specimens 
exhibited were hatched from cocoons obtained when digging 
in our garden at Croydon. GLADYS H. FROGGATT. 
SENSE OF SMELL IN FISHES.—A very important 
paper by G. A. Parker and R. E. Sheldon, bearing upon this 
much-debated subject, has come to hand. It forms Document 
No. 775 of une Bulletin of the U.S.A. Bureau of Fisheries. 
Summarised, the authors’ investigations show that :— 
“(1) A current of water passes through the nasal cham- 
bers of many fishes in a direction from anterior to posterior. 
It may be produced by ciliary action (Ameiurus), by pres- 
sure due to the action of the respiratory muscles (Fundulus), 
or it may be a part of the true respiratory current (d/uste- 
dus). 
““(2) By means of this current, dissolved substances in 
the water are brought into contact with the olfactory sur- 
faces.’’ 
“(3) Fishes distinguish packets containing hidden food 
from similar packets without food.’’ 
““(4) The power of distinguishing the two classes of pac- 
kets is lost when the olfactory tracts are cut, when the an- 
terior olfactory apertures are stitched up or when the aper- 
tures are plugged with cotton wool. It is revived on re- 
opening the apertures by taking out the stitches or removing 
the cotton wool.”’ 
““(5) dfustelus and Ameturus discover their food chiefly 
through the olfactory organs for this purpose.”’ 
“(6) Mustelus, Fundulus, and Ameiurus use the olfactory — 
organs to scent food much as land animals d~- these organs 
are true organs of smell, i.e., distance receptors for the chemi- 
‘cal sense.”’ 
Among Australian fishes, I might add, the manner in 
which the bait is taken, say, by a Bream (Chrysophrys), leads 
-one to supose that the sense of smell is almost constantly made 
use of ; whereas in the case of the Kingfish (Seriola), a rush is 
generally made at whatever is made to look attractive. The 
latter method is largely the case in all our game fishes, in fact, 
and implies that sight only is used under such circumstances. 
Yet cases are frequently to be seen in which apparently the 
‘sense of smell has been also used.—David u. Stead. 
