i'^l 



THE ANNALS 



AND 



MAGAZIiNE OF NATURAL 1118T0KY. 



[NlXTIl SKRllCS.] 

 No. 10. OCTOBI*]R 1918. 



XXVir. — On the Ii'iC'S and Vailnh'on of ih", Edihif Fio<j^ 

 RaiKi e.sculent:i, L. 13y Gr. A. 13ouli:.\uki:, b'.ll.S. 

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

 ApTlili all I liave written in the past on this conmion 

 Bati-achiati, it may seem surprisinL; that I should think it 

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

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

 l!itin<^ niaterial*, in the course o£ recently reviewing- wiiieii 

 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 S()ecies represented by less 

 extensive nuiterial. Not that I think inconstancy in one 

 case invariably follows in another, but such examples teach 

 caution, and should be a warning to the inexperienced. 



Considering modern tendencies in zoography, it cannot be 

 too often repeated that the method of describing so-called 

 S])ecies and subspecies from ti^ingle 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. 



t "On aura beau multiplier les especes, on arrivera toujours ace 

 r^sultat que la description exacte d'uu sujet pris au hasard, paruii 

 Boixante recoltes sur des points divers dun nieme rivage, ne pourra 

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

 Montpell. vii. 1871, p. 511. 



Ann. cC; Maij. N. IILst. Scr. 9. Vol ii. 19 



