192 A GARDEN DIARY 



and to the evolutionist tadpoles must always 

 prove interesting acquaintances. They provide 

 us with at least an inkling as to the fashion 

 in which your unadulterated water-breather may 

 have been converted into an air-breather, and 

 by means of no process more recondite than 

 that of losing its gills. That such conversions 

 do take place, and under certain circumstances 

 remain permanent, has been proved in the well- 

 known case of the axolotl, or Mexican gilled 

 salamander. As long ago as the year 1867, while 

 conducting some experiments at the Jardin des 

 Plantes, M. Dume"ril startled the zoologic world of 

 Paris by communicating the fact that, out of a 

 number of axolotls kept in the collection there, 

 about thirty had left the water, and had assumed 

 the form of what had hitherto been regarded as 

 an absolutely distinct genus of land salamander, 

 known as amplystoma. This discovery made at 

 the time a prodigious stir, not so much on account 

 of a water-breathing creature losing its gills, and 

 becoming an air-breather, for that was a phe- 

 nomenon which might be seen every spring, and 

 in most of the ditches round Paris, but because 

 the axolotl was known to breed, and that it 

 therefore appeared to indicate the exceedingly 

 anomalous case of a larval form proving to be 

 fertile. 



How the feat of transformation was to be 

 actually witnessed was the next problem, and it 



