1S7S.] 259 



pillars in question being rendered luminous by having accidentally crawled in lumi- 

 nous matter. Their chief beauty, as I remember it, was in the evenness and 

 regularity of their illumination, the railway train simile being very exact in this 

 respect. I am not learned in Entomology, much as I always delight in using such 

 powers of observation as I, in common with most ' country born and bred ' people 

 naturally possess, otherwise I should have at once recognised the value of this seem- 

 ingly new observation. 



" I regret very much indeed that I should now have got no specimens of tliese 

 caterpillars ; though, from mere curiosity and admiration of their beauty, I did, at 

 the time, actually skin and stuff several of the most striking kinds of each of the 

 three varieties named ; but long before we could emerge from tlie Wilds, these deli- 

 cate specimens had been utterly ruined. 



" I never preserved any of these caterpillars alive, so as to follow their meta- 

 morphoses, so cannot identify them with any particular moth." 



I have Mr. Bigg-Wither's permission to publish these notes, and I can only 

 express a hope that lepidopterists may find them as interesting as I do. Mr. H. W. 

 Bates informs me that in all his South American wanderings, he never met with 

 any similar instance ; but the Amazon district in which he travelled so much is close 

 to the Equator, while Mr. Bigg-Wither's investigations were confined to the Tibagy 

 and Ivahy rivers, under the tropic of Capricorn, 1500 miles further south, a district 

 never visited by collectors. Mr. Keith Johnston, however, tells me that in his recent 

 journey in Paraguay, he, though not an entomologist, was struck by a curious cater- 

 pillar which he often observed in that country, and which, from his description, is 

 apparently the same as that figured by Mr. Bigg- Wither. It was of a very bright 

 (almost emerald) green, with long mossy filaments on the back, and was possessed of 

 urticating properties, as the natives gave warning. Mr. Johnston, however, never 

 observed any phosphorescence in these larva?, possibly because he never camped out 

 by night in the forest, — a habit compulsory in Mr. Bigg-Wither's case, from his sur- 

 veying duties. The district in which Mr. Johnston saw these larvae is close to that 

 traversed by Mr. Bigg-Wither. 



The only case of phosphorescence in tlie Lepidoptera known to me, is that re- 

 corded by B. A. Gimmerthal, as occurring in the larva of Noctua occulta, in Bull. 

 Soc. Nat. Moscou, 1829, vol. i, p. 140. In Ann. Soc. Ent. France, 1832, p. 424, this 

 fact is referred to by MM. St. Fargeau and Eambur as entirely unknown before ; but 

 M. Boisduval, without giving any instances, observed (I.e. p. 425) that he was awaro 

 of the luminous property in larvfc (presumably Lepidopterous). 



From a notice in Silbcrmann's Rev. Entom., i, p. 2GG (quoted by Kirby and 

 Spence, Introd., 7th ed., 18.j6, p. 510 ; not in 1st ed.), Boisduval's knowledge was 

 founded on an observation of some caterpillars found on grass stems, one hot evening 

 in June, and which spread a phosphorescent light. These, he thought, belonged to 

 Mamestra oleracea, though they seemed unusually largo. They were certainly not 

 the larva of Noctua {Folia) occulta ; and none of them assumed the pupa-state, 

 either from want of care or from their luminosity arising from disease. 



As the economy of the European NoctuidcB is so well known, I think it may 

 be fairly assumed that the luminosity in the two instances mentioned by Gim- 

 merthal and Boisduval is abnormal (however inexplicable), and not persistent, as is 

 apparently the case in the South American larvtc ob.icrvod by Mr. Bigg-Wither. 



