BY J. J. FLETCHER. 361 



former of which has (for a period of six years) a mean annual rain- 

 fall of 13-66 inches, and 45 as the mean annual number of rainy 

 days, as compared with 49-86 inches and 153 days respectively 

 for Sydney (for 29 years). "^ Hence in such a locality as this the frogs 

 must sometimes be in great straits to get rid of their ova, if their 

 oviposition is of the ordinary character ; and the young must often 

 develop under difficulties unless there is some adaptation to cir- 

 cumstances. Dr. Giinther (I.e. p. 378) also says : " The observa- 

 tion of A. W. Aitken {Trans. New Zeal. Inst. ii. 1870, p. 87) 

 that in tropical parts of Australia certain frogs form a hollow ball 

 of clay, containing about half a pint of clear cold water, in which 

 they sojourn during the drought, is probably also indicative of a 

 provision to secure the safety of the spawn and young." Further 

 information about this species as well as its identification are desir- 

 able. Mr. E. B. Sanger statesf that on one occasion he found in 

 pools collected from rain which had fallen two days previously, "the 

 first time for certainly two years," on the stony plains of the 

 central Australian desert, a greab number of tadpoles and a 

 young fish ; and as to how they came there he concludes " that 

 the eggs must have been buried rather deeply, and then when the 

 moisture reached them developed rapidly." On this subject Mr. 

 Aitken also says (I.e.) " There are districts often exceeding 5,000 

 square miles in extent in the interior of the Australian continent 

 in which there is no surface water for many months, and in some 

 instances for years ; yet as soon as rain falls in sufficient quantities 

 to fill the water-holes they are swarming with young frogs." Fur- 

 ther on he again speaks of swarms of tadpoles peopling the water- 

 holes after rain. 



Since 1881 I have carefully made notes of the dates at, and 

 the circumstances under which, I have met with frogs breeding; 

 with the result that, taking one year willi another for several 

 years, e.g. the three years 1884-86, some frog-spawn was met with 

 in every month in the calendar. Not that there was anything 

 abnormal about these years, for a similar result would be quite 

 normally obtainable by regularly collating one's observations for 



* "Rain and River Observations, 1887, p. 41." 

 t Ameiican Naturahst, 1883, xvii. p. 1185. 



