PERONEA CRISTANA. 219 



with the main stem. In this position they were exceedingly 

 well protected from observation, and could hardly be detected, 

 unless one saw the "buttons" raised clear of the twig; and 

 they were not easily detected with the aid of the buttons, because 

 these resembled very strikingly whitethorn buds. 



March 19th, 1916, was a very warm, sunny day, and the 

 moths were almost lively, for them, for P. cristana is one of the 

 most sluggish moths I know. One example was found resting 

 on the muslin, and on this being touched it flew to the other side 

 of the enclosure. On March 26th I untied the bottom of the 

 muslin sleeve or enclosure, and found that one imago was 

 dead, although it was quite limp, and had evidently recently 

 been alive. It was amongst the dead leaves which had accumu- 

 lated at the bottom of the sleeve. The remainder were alive, 

 and seemed quite strong and healthy. On being disturbed they 

 flew off the twigs on which they were resting, and settled on the 

 jnusliu sides of the enclosure. I counted six of them on this 

 occasion, and the remainder were no doubt somewhere inside. 



I should say that when placing the moths in I had put in 

 the sleeve a thick piece of dead oak branch covered with lichen, 

 which I thought would possibly be a suitable object for them to 

 ■winter upon. Although I frequently looked this over, I could 

 never see a moth resting upon it, and on this day I took it 

 away. On May 17th I emptied out the sleeve, and found that 

 all the moths were dead, although I had seen one alive a few 

 days previously. 



I then carefully examined with a lens the whole of the 

 whitethorn bush and also the sleeve for ova, but the search was 

 entirely without success, and thus my first attempt ended in 

 failure so far as obtaining eggs was concerned. I had, however, 

 gained certain experience, and proved that the supposed habit 

 of the imago to hibernate was a fact : and this, of course, meant 

 ■that the ova were deposited in the spring, and not in the 

 autumn. 



Thinking the matter over during the summer of 191(5, I 

 -came to the conclusion that what wa^ wrong in my method was 

 something in the spring treatment, wliich I must try and vary 

 in some way ; but that the winter treatment was correct. 



In October of that year 1 procured a fresh supply of moths, 

 dug up and potted another whitetborii bush, enclosed it in the 

 sleeve that had served the previous winter, and stood it in the 

 same spot that had been occupied (ui the former occasion. I 

 should here say that the mothb enclost-d were twelve in number 

 and that they consisted of two of tlie most abundant forms, 

 which I did not require for my own or iriends' series, abs. nigrana 

 and semiustana, half of each ; to these I added, a few days later, 

 three examples of ab. cristdlma, all males. 



On April 1st, 1917, I examined th^' contents of the sleeve, 



