THE PYRENEES IN 1920. 7 



habits, the young larva. might have to travel a little distance to get to 

 its particular plant (that it can both feed and travel under snow is 

 almost certain), but in such species the 2 probably goes to rest in 

 proximity to, if not on, or under, the foodplant. In many Alpine 

 species too, the larvae probably make their first meal off the eggshell ; 

 this I know to be the case with all those Erebia species mentioned 

 already as having laid eggs in boxes. This would provide them with 

 sufficient food to enable them to travel a moderate distance. The 

 grass feeding larvae, like the Frebias, will never have more than an 

 inch or two to move. All the eggs of the Erebia species, which I had, 

 hatched in thirteen to fifteen days ; it therefore must often happen 

 that the eggs of those species which lay in late August, or even mid 

 August (glacialis, goante, euryale, pronoe var. pitho, gorge, etc.), are 

 snowed over before they hatch. This fact justifies my previous 

 assertion that young larvae can feed and travel under snow ; if not, we 

 should have to accept the almost impossible theory that the larva of 

 any Alpine species of Erebia can hybernate at will in any stadium 

 from newly hatched to six weeks old, according to the weather. This 

 affects, more or less, all species which do not hybernate as an egg. 

 It may be useful to add that the Alpine grass keeps fairly green under 

 the snow, well into December, so that so far as the condition of the 

 vegetation is concerned, there would be nothing to prevent the larvae 

 feeding for the requisite length of time to attain a certain standard of 

 development before commencing to hybernate. 



In conclusion, we have two irrefutable facts to reconcile : firstly, 

 the meteorological conditions pertaining to the high Alpine regions, 

 and secondly, the presence of butterflies in those regions. There have 

 been, without doubt, in past centuries, repeated cycles of bad summers, 

 in which the ordinary duration of the flight period of all Alpine 

 species will have been lessened by half, a quarter, or three-quarters, 

 their usual length ; and if we assume, not merely that the species are 

 unable to lay under snow, but that to do so is not a completely natural 

 function with them ; then it follows that the repeated decrease in the 

 amount of ova laid each year, reduced in proportion with the flight 

 period of the species, must have so thinned the numbers of the species 

 affected, that gradually, first one then another must have become 

 extinct, until the whole butterfly Fauna of the high Alps would, long 

 since, have ceased to exist. 



The Pyrenees in 1920. 



By DOUGLAS H. PEAESON, F.E.S. 



The Pyrenees had long been calling and after six years of enforced 

 home keeping they clamoured with a voice that could no longer be 

 disregarded and my brother and I decided upon a trip. 



Leaving London early on June 23rd, we arrived in Paris in the 

 evening and took the night train for Luchon, where we were timed to 

 arrive at about 8.30 p.m. In passing through southern France it was 

 interesting to note that oxen were almost universally used for farm 

 work instead of horses, and it was quaint to see oxen drawing a 

 modern hay cutter or reaping machine. We were landed at 

 Montrejeau about mid- day with a wait of 5 hours before the train 

 went on for Luchon, and after having disposed of an excellent lunch 



