THE ANNALS 



AND 



iZIiNE OF NATURAL HISTOB 



[NINTH SICKLES.] 

 No. 10. OCTOBER 1918. 



XXVII. — On llie Rue s and Vm lit ion of lli> Edible Frog, 



Rana esculenta, L. By G. A. BoufJ£NGtiit, L<\It.S. 



(Published by permission of the Trustees of the British Museum.) 



After all I have written in the past on this comnfon 

 Batrachian, it may seem surprising that I should think it 

 worth while to revert to the subject. The reason is that it 

 is far from exhausted ; that I have never ceased accumu- 

 lating - material*, in the course of recently reviewing which 

 I perceived characters hitherto overlooked ; that it was 

 desirable to test the value of certain differences appealed to 

 within the last few years by advocates of the extreme multi- 

 plication of species ; and that it is always useful to deal with 

 individual variations, when large series of specimens are 

 available, in order, by showing the instability of certain 

 characters, to ensure a more correct appreciation of their 

 importance when treating of allied species represented by less 

 extensive material. Not that I think inconstancy in one 

 case invariably follows in another, but such examples teacii 

 caution, and should be a warning to the inexperienced. 



Consideiing modern tendencies in zoography, it cannot be 

 too often repeated that the method of describing so-called 

 species and subspecies from single specimens f or from at 



* About 800 specimens are now before me, selected from at least 

 twice as many that have passed through my hands. 



f " On aura beau multiplier les especes, on arrivera to uj ours a ce 

 rt5sultat que la description exacte d'un sujet pris mi hasard, parmi 

 soixante recolt<5s sur des points divers dun meme rivage, ne pourra 

 convenir a aucun des cinquante neuf autres." Duval-Jouve, Mem. Ac. 

 Montpell. vii. 1871, p. 511. 



Ann. & Mag. N. Hist. Ser. 9. Vol. ii. 19 



