VARIATION AND LOCALITY 129 



are thus found in many places. Coutagne instances Muller's 

 observations in Denmark, his own series from the Jura, etc. 



Locality B. Vonges (C6te d'Or), 242 hortensis taken at ran- 

 dom, showed 128 with light peristomes (either more or less pinkish 

 or quite white) and 114 with dark brown peristomes; together 

 with 26 nemoralis all with the usual brown peristomes. 



Of the hortensis 50 were in ground-colour opalescens and 1 

 roseus; and in shape 5 were umbilicatus. 



Locality C, about 3 kilometres from B. There were found 35 

 hortensis, of which 20 had light peristomes and 15 brown; to- 

 gether with 7 nemoralis. 



Of the hortensis none were opalescens; 18 were roseus and none 

 has the shape of umbilicatus. 



Locality D, about 1,200 metres from B. 147 hortensis , of 

 which 4 had light peristomes and 143 had brown. No nemoralis 

 were found. 



None of the hortensis were opalescens or roseus, but 30 were 

 umbilicatus. 



In these localities intermediates of every grade existed be- 

 tween the well-characterised opalescens, roseus, or umbilicatus, 

 and the other forms, but there were no intergrades between the 

 other nemoralis and the smaller hortensis, about which there 

 was no hesitation. In the next locality a very different state 

 of things was found. 



Locality E. Banks of the Yvette at Orsay (Seine-et-Oise). 

 The actual numbers are not given, but we are told that 58 per 

 cent, were hortensis, 33 per cent, nemoralis, and 9 per cent, inter- 

 mediate. As at Honfleur, the hortensis had white peristomes, and 

 the nemoralis brown. Coutagne's visits to this locality were 

 in 1878 and 1880, and he calls attention to the fact that Pascal 

 found similar intermediates in the same neighbourhood in 1873. 



The two species, in Coutagne's view, when they occur to- 

 gether, can generally be sorted from each other with perfect 

 confidence, and it is only in exceptional localities that these 

 intermediates occur. Whether they are hybrids, or whether 

 sometimes the species in their variations transgress their usual 

 limitations is regarded both by Coutagne and by Lang as a 



