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. Duméril 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 
