JULY 28, 1892] 



NATURE 



307 



Club Hotel. At one time Gayndah was the centre of a wool- 

 producing district, and bears evident signs of having seen a 

 better day. 



Intent on meeting with Ceratodus, I made my way to Mr. 

 Thomas Illiclge, the postmaster of Gayndah, to whom I had 

 been recommended, and I gladly take this opportunity of ex- 

 pressing my thanks to him, not only for the valuable help and 

 information which he gave me, but for many acts of kin Iness 

 which added greatly to the pleasure of my stay in Gayndah. I 

 may here also express my thanks to my friends, Dr. Cole and 

 Messrs. Frank and Virgil Connelly, from whom — though a 

 complete stranger — I received most valuable help. If a 

 naturalist wishes to meet with genuine kindness and every 

 possible assistance, I can warmly recommend Gayndah to 

 him. 



One of the first things I learnt was that Dr. Siemen, of the 

 University of Jena, had recently come to the Burnett district for 

 the purpose of securing the eggs of Ceratodus, and the various 

 development stages of Platypus and Echidna ; and not only 

 this, but that he had secured the services of the available blacks. 

 I must confess to a feeling of something like chagrin at having 

 come so far to meet with, apparently, no chance of success in 

 what was my main object. 



After sleeping over my preliminary disappointment, I deter- 

 mined on carrying out the only plan possible, which was to 

 obtain one or two boys accustomed to the river, and, with their 

 help, to at any rate get Ceratodus, and, if possible, the eggs. 

 It was now well on in September — the time at which Mr. 

 Caldwell had found that the animal had laid eggs — so there was 

 still hope that I might secure them. Perhaps it may be well 

 here to state briefly the special interest which attaches to this 

 particular form Ceratodus. As you all know, there are two 

 groups of animals — the fishes and the amphibia — of which the 

 first live in water, and breathe by means of gills, whilst the 

 second either spend, as the newts do, their whole life in 

 water, breathing by means of gills, or else, like the frogs, 

 spend the early part of their life in water, breathing by gills, 

 and then come out of the water and breathe by lungs just as 

 reptiles and mammals do. 



Now there is a very small group of anitaals known as the 



Dipnoi, which are, we may say, intermediate between the fishes 



and the amphibia. They are neither so lowly developed as the 



fishes, nor so highly developed as the amphibia — in fact, they 



may almost be described as "missing links" which still exist, 



and show us the way in which air-breathing were evolved from 



water-breatbing animals. If we simply went by their external 



appearance we should class them amongst fishes, which they 



closely resemble in many respects. Now, fishes have what is 



known as a swim-bladder, which is merely a long hollow process 



developed from the oesophagus. This serves, probably, mainly 



I as a float, and not at all for respiratory purposes ; but in the 



I small group. Dipnoi, of which Ceratodus is one, this same swim- 



I bladder becomes modified to act as a lung. Not only this, but, 



f whereas in fishes the impure blood which is carried from the 



■', body to the heart passes to the gills, is purified there and then 



\ goes straight to the body, in the Dipnoi part of the blood goes 



i from the heart to the lung, and then is carried back again to a 



chamber in the heart specially developed for its reception. In 



fact, in the Dipnoi we can see some of the earliest stages in the 



evolution of important organs of the body as we now find them 



in all animals above fishes. 



' At the present time only three examples of the Dipnoi are 



known to exist in the world — one form, Lepidosiren, lives only 



in the Amazon ; another, Protopterus, is only found in tropical 



■ Africa ; and the third, Ceratodus, occurs only in the Burnett and 



Mary Rivers, in (Queensland. In past times, however, Ceratodus 



lived in other parts, such as Europe, as its fossil remains testify ; 



and in Australia Prof. Tate has recorded the presence of its 



teeth in the strata of the Lake Eyre basin. In fact, Ceratodus 



is one of those rare forms of which fossil remains were found and 



named before the living form was discovered. 



The habits of Protopterus have been studied, and it is stated 

 that during seasons of drought it makes a cocoon of mud for 

 itself, and breathes by means of its lung. On account of this 

 habit, these forms have often been called mud and lung fishes. 

 My main aim, then, was to find the eg?s of the Ceratodus. 

 From Mr. Caldwell's published notes, which are only too brief, 

 I knew that it deposited them much like some amphibians, such 

 as the Axolotl, do, on weeds, and that he had found them in 

 September. 



NO. T 187. VOL. 46] 



To return now to Gayndah. I purchased a tent and provi- 

 sions, and having hired two boys accustomed to the river, started 

 away to camp out some few miles up the Burnett. The country 

 was very dry and sandy, with all the creeks empty of water. 

 The outcropping rocks are granitic, with basalt capping the hills 

 around, and the disintegration of the granite appears to give 

 rise to a vast amount of sand. Along the river itself there is an 

 alternation of large sandbanks, where the stream is shallow, and 

 of long deep pools with great granite masses. The banks are 

 bordered by bottle-brush trees (Callistemon), which at that time 

 were crimson with flowers, and alive with thickheads. Leaving 

 my stores to find their way to an appointed spot, I kept by the 

 river bank on the lookout for weeds, for without these it was 

 hopeless to set to work. After a short halt at a station close to Mt. 

 Debatable, where the sociable wasp (Polistes ferrugineus) was 

 busy making its nest in the verandah, I walked on until we were 

 some six or seven miles out of Gayndah but there was not a trace 

 of weed in tbe river. Close in to Gayndah, there was a small 

 quantity, but where we expected to find a good supply there was 

 none at all, owing apparently to heavy floods which in the last 

 wet season had swept down the river. Accordingly we turned 

 back and pitched our camp not far from Gayndah. It was 

 evening by the time we were settled down, and too dark to see 

 the eggs, so we lit a fire and fished. It was a lovely moonlight 

 night and the coolness was delightful after the heat of the day. 

 The river is full of fish, and we caught sand eels and mud eels, 

 jew- fish, perch, and bream, but not a single Ceratodus — or, as 

 they call it locally, salmon. Turtles kept rising to the surface 

 and showing their black heads above the water, and every now 

 and then when we sat still we could recognize a Platypus. In the 

 morning I set to work to search over the weed. One of my boys 

 stripped and went into the river for it, whilst I sat half in and half 

 out of the water looking carefully over each piece. In the hot 

 blazing sun this was not enjoyable, and after some hours' work, 

 and not the slightest sign of an egy;, and when the small patch of 

 weed was pretty well exhausted, I sat down to think, and 

 questioned my boys closely as to where there was more weed. 

 A little way on the other side of Gayndah they told me there was 

 a backwater usually full of weed. Why they had not told me of 

 this before I could not imagine, and the remarks made probably 

 conveyed this idea to them. However, we were close to the end 

 of this weed, and as we had to get to some more, I sent one boy 

 into Gayndah to procure help in removing our camp, for which, 

 fortunately, I had made previous arrangements In the afternoon 

 I finally exhausted the weed and myself with no result, and for a 

 change set to work to turn over a few logs. Amongst planarians, 

 Geoplana ccei-ulea 2LXi6. variegata ; amongst earthworms, Crypto- 

 drilus piirpureus ; amongst frogs, Limnodynastes tasmaniensis 

 and Hyperolia marmorata ; and amongst lizards, species of 

 Pygopus, Hinulia, and Egernia, and a small mammal, a species 

 of Antechinus, rewarded my efforts, but everything was too dry, 

 though the season was early, for anything very much in the 

 nature of worms. Along the river banks endless numbers of the 

 beautiful butterfly Danais erippus attracted my attention. It was 

 feeding on tbe plant (Lanthana) along with which it has been 

 introduced. In the river itself was to be seen the curious water 

 lizard Physignatlms lesueurii, of which we caught a small speci- 

 men, and also the frog Hyla lesueurii, whilst the Callistemon trees 

 contained plenty of a little green species of Hyla which the boys 

 used as bait for fishing, and which appears to be new to science. 

 I also caught this same frog on window panes at night in Gayndah, 

 where, like a moth, it goes to the light. As the evening came 

 on the mullet began to jump. They feed especially on a fila- 

 mentous alga which grows in the water, and contains numerous 

 crustaceans, especially a prawn-like form, for the sake of which 

 they eat the alga. The latter is used as bait for them. At 

 night we caught a large mud eel, five feet long,which we eagerly 

 drew into land, thinking it to be a salmon. I tried sugaring the 

 trees, but it was of no use, not even a single ant put in its 

 appearance, and thus ended another day of hard work and 

 disappointment. 



In the morning I had my boys up by 4 a.m., and before six we 

 were out of camp, and by nine o'clock had our tent pitched by 

 the side of a backwater on the other side of Gayndah. This con- 

 tained plenty of weed, and here I spent some days. We pro- 

 cured a long pole, with three prongs at the end, to pull the weed 

 up with. We used to get a large bucketful at a time, and then 

 go over it piece by piece. This process had to be conducted 

 under a hot sun, and the result was that my arms became swollen 

 j to about double their natural size— so m^^ch, indeed, that I could 



