30 Hybridisation of Amphibians [January, 
It is sickening to see Bestiarians ready and willing to 
inflict inconvenience, pain, or death on “ all sorts of animals” 
for any purpose save the acquirement of knowledge. May 
we not legitimately infer that a love for ignorance is with 
them more powerful than the reluctance to give pain to 
sentient beings ? 
As regards Mr. Bell’s insinuation that hospital physicians 
intentionally abuse the opportunities of their position to 
make experimental studies upon their patients, we regard it 
as utterly unfounded, and we think it deplorable that any 
person with the slightest pretensions to culture should en- 
tertain, and what is worse, should seek to promulgate, so 
baseless a notion. We are glad to find that the “ Standard,” 
whilst considering Drs. Ringer and Murrell open to the 
charge of indiscretion, is yet very far from endorsing the 
charges brought by its correspondent. This is merely what 
might have been expected from its honourable antecedents. 
Every scientific man must remember that its conduct anent 
the Bestiarian hubbub has formed a refreshing contrast to 
the position taken by two of its daily, and still more by one 
of its weekly, contemporaries. 
VI. ON THE HYBRIDISATION OF AMPHIBIANS 
AND THE PRINCIPLES OF REPRODUCTION. 
<!|v^N extended series of experiments on the hybridisation 
of certain varieties and species of frogs and toads 
has been conducted by Professor E. Pfliiger. The 
results, which have just been made public, are of the 
highest scientific importance, and merit the careful attention 
of naturalists. 
The author establishes, in the first place, that those 
differences which determine the character of a race by no 
means compromise fertility. As regards the species experi- 
mented upon it appears that the large Berlin lake-frog and 
the blue fiogs ol the Rhine are not species, but merely 
varieties of Rana escidenta. On the other hand, R. arvalis 
(s. oxyrhinus) is not a variety of R. fusca, the brown grass- 
frog, but a distinct species. 
