THE YOUNG NATURALIST. 



253 



lubricipeda and mentkastri vary like caja fugitively. Monacha varies from 

 light to almost black, every intermediate variety being seen. 



Betularia has every intermediate variety, from nearly white to deep rich 

 cold brown or black : in my two long rows of it they run imperceptibly into 

 each other. Bepandata has several named varieties and several recurrent 

 varieties not named. Mr. Weir's form from Shetland and Conversaria Hub. 

 are the extremes it runs to, between these there are so many recurrent forms 

 that I have had to reject some for want of room in my cabinet. One very 

 dark form from Burnt Wood, where it is ever recurrent should be called 

 Fumosce, there, it is always more or less (often more) smoky. Biundularia 

 varies from light grey to rich dark smoke colour at Petty Pool Wood, Dele- 

 mere Forest, and also at Burnt Wood, Staffordshire, every intermediate shade 

 being found freely. G. obscurata varies according to the geological forma- 

 tion it lives upon, but as it always eats the same food in all places or dies, 

 this is to my mind the key to variation as a general rule — geological not 

 geographical. When different pabulum is taken a different result may be 

 expected sometimes, but the food of the plant gives the insect its variation, 

 more than the latitude it is born in. 



I am far exceeding the limits I had set myself, but there are so many 

 species of British moths having intermediate varieties, that there is no place 

 to stop for any one who has made variation his study, I will, therefore, rush 

 on. I need hardly name H. leucopkearia or H. defoliaria, both have recurrent 

 permanent varieties. Em. albulata has every intermediate colour, between 

 white and dark fuscous, the smoke coloured ones have been named by Mr. 

 Weir, but I cannot tell where the name begins to apply, they are so very inter- 

 mediate. I took some dusky ones at Conway this year, they can hardly be 

 variety TImles ! Weir. Eup. sobrinata runs from light to nearly black as bred 

 this year at Hoy, by Mr. Curzon. Eup. rectangulata from light pea-green to 

 almost black (here in my garden from the same batch of eggs) in regular 

 gradation. But for real variation commend me to Yp. elutata, I have 

 two rows, and Mr. Curzon has brought about the same number from 

 Hoy, hardly any of his are like any of mine, but all are different from 

 each other, yet in both cases they form series of types as does A. grossu- 

 lariata. My collection of varieties of that species are arranged under 

 letters from A to Y. If I were combating Mr. Robson's paper I could 

 shew that that species does go into forming permanent varieties, but my only 

 object is to stop the error that Mr. Sheppard set running off so many years 

 ago, viz. that " there were no intermediate varieties." To do this I will just 

 write out a few other species that have intermediate varieties, and so satisfy 

 the most exacting reader. 



