24l2 DAKIN, 



distended specimen was killed in such a way that most of the air was retained 

 — the lungs were found to reach almost to the posterior end of the body cavity. 

 The other common peculiarity of the frog is that when stroked or tapped in 

 order to produce the swollen state the animal often utters the most extraordinary 

 cries. They can he described exactly by the words used in reference to Philocry- 

 phus flavoguttatus (the Eastern Burrowing Frog) in Lucas and Le Souef's Ani- 

 mals of Australia: — "and sometimes on such occasions it cries in the weivdesi 

 fashion just like an infant." 



The first peculiarity mentioned above seems, as suggested by Fletcher, to be 

 common to very many burrowing frogs. 



A few weeks after the animals first notified their existence, a number of small 

 holes about the diameter of a penny were to he seen on the surface of the ground 

 If these were followed down, each led to a little chamber in which a frog was 

 sitting. Evidently the animals came to the surface at night. They were always 

 about IS inches below the surface in the day. The excavation never went down 

 vertically from the opening, but took an irregular course, with quite a gentle 

 slope, so that, measured along the burrow, each frog was three feet or more from 

 the surface aperture. 



There is something of interest in the peculiar rhythm of the croakers. As a 

 rule not a sound was heard before 4.30 p.m., and the orchestra ceased about 

 4. 3H to 5 a.m. Now this rhythm was set up before the frogs connected their 

 underground caves with the surface. What determined the rhythm, and the 

 hour of starting ami ceasing.' Day and night could not have been appreciable, 

 and the sun was still shining strongly when the evening chorus began. It seems 

 doubtful whether temperature changes would have provided stimulus sufficient at 

 the time when the frogs started, especially when the depth below ground is noted. 



Diurnal rhythm is not an uncommon feature in animal and plant life, and, 

 once set up, it is sometimes possible for it to continue without the continuance of 

 the stimulus, 'thus the marine Protozoan Noctiluca, when taken into a dark room, 

 will only give forth phosphorescent displays by night, although there is no light 

 whatever in the room during the whole '-!4 hours. The little Oralis also per- 

 forms its sleep movements regularly at sundown and sunrise, even if removeu lo a 

 dark room. No satisfactory explanations of the above are yet forthcoming. Per- 

 haps the croaking habit of frogs is a feature of a similar kind. 



In making excavations in order to obtain frogs, the author discovered, much 

 to his surprise, that eggs had been laid underground in places where there was 

 no sign of water. Every two or three feet apart, and at depths of about 18 inches 

 below the surface of the soil were small chambers about 3 inches in diameter. 

 They appeared to have no passages leading to or from them. Each chamber was 

 tilled with a mass of eggs enclosed ill, and separated by, a mass of frothy mucus. 

 The most noteworthy feature was I he regularity of this method of deposition. 

 No traces of eggs were found in any other places, and there was no more ten- 

 dency apparently to deposit them near a pool of water than at a distance from 

 it. The soil remained for weeks after this first discovery of the eggs in exactly 

 the same condition — i.e., light sandy soil containing organic matter and in a mod- 

 erately dry condition. It ran easily through the fingers, and rain percolated 

 through it rapidly, showing no tendency to collect on the surface. 



The eggs numbered 50-100 in each mass. They were somewhaf large ami 

 without pigment. In order to trace the general features of development, small 

 quantities of spawn were placed in little caverns made by the author in soil, the 

 whole being contained in a large dish. To get still nearer the normal conditions. 





