Royal Physical Society. 31 



boundary of the valley of Assam. A guava tree grew in the 

 garden in front of her house, and on this she placed such speci- 

 mens as she could secure, and when once placed on the tree they 

 did not in general seek to leave it, at least until they assumed 

 the perfect state, a convenient habit of which Mr M'Nab found 

 the advantage in rearing his specimen. On returning to this 

 country Mrs Blackwood endeavoured to bring some living speci- 

 mens with her, but having found the trouble and attention they 

 required too great, she, after bringing them safely to Calcutta, 

 entrusted them to a friend, who shortly followed and brought 

 them in good condition overland till they reached the Medi- 

 terranean Sea, when they died, — even that genial climate ap- 

 parently not having suited them. 



Mrs Blackwood next tried to introduce them by eggs. She 

 got a parcel of eggs transmitted to her by post, but as they had 

 not come out at the period she expected, she left them behind on 

 going out of town (despaired of as regards hatching, but preserved 

 as specimens), when to her mingled pleasure and regret on her 

 return, she found that many of them had come out and died in 

 the box in which she left them. Encouraged by this result, she 

 again got a supply of eggs in the spring of 1854, and keeping a 

 more careful watch upon them, she had the pleasure to find a pair 

 come out on the 9th and 10th May : one or two followed every 

 week till the end of May, when a week or so of cold weather 

 occurred, during which no more came out ; but when fine wea- 

 ther again returned in the beginning of June, they again began 

 to come out in greater numbers. It was one or two of these 

 which were entrusted to Mr M'Nab, and he succeeded in rear- 

 ing to perfection the specimen which became such a favourite. 

 He carefully noted down the periods of change in the insect, 

 and such other circumstances regarding its habits as struck 

 him, and he has been kind enough to furnish me with a note 

 of these which I have embodied in the following paper. 



On the young insects being hatched considerable difficulty 

 was felt about their food. Of course the first thing thought of 

 was the guava, and leaves of it as well as of various other allied 

 Myrtacese were tendered them, but whether it was that the 

 leaves having been plucked, and not growing on their stalk, 

 did not suit them, or that some little time after their eclo- 



