382 SUMMARY OF CURRENT RESEARCHES RELATING TO 



elongated ; in Galleria melonella tliey are associated with an arbores- 

 cent growth. In most Lepidoptera three terminal tubes are formed 

 on each side. Two first appear and one bifurcates. The author notes the 

 fundamental importance of the basilar trunk, the structure of the system in 

 the more jirimitive Tracheata, discusses the theory of atavism, and finally 

 distinguishes, as above, the three types of urinary system in Lepidoptera : 

 (1) normal, with six vessels joining the intestine by two basilar trunks 

 (majority) ; (2) atavistic or embryonic, with two simple vessels (Tineola 

 biselliella, Tinea pellionella, Blahophanes rusticella) ; and (3) abnormal 

 {^Galleria melonella) with two ramified trees. 



Cause and Extent of Colour-relation between Lepidopterous Pupae 

 and surrounding surfaces.*— Mr. E. B. Poulton has made a series of 

 experiments with lepidopterous pupse for the purpose of testing the cor- 

 rectness of his idea that the relation between the colour of lej)idopterous 

 pupse and their surroundings was a physiological one, and that the reflected 

 light would be found to act on the larva at some time before pupation, and 

 not on the pupa itself; it also seemed to him to be probable that the 

 sensitive area might be defined by experiment. 



Experiments made on Vanessa lo, in which six mature larvae were 

 placed in a glass cylinder surrounded by yellowish-green tissue-paper, 

 resulted in five changing into the rarer yellowish-green form of pujia. Over 

 700 specimens of V. urticse were experimented on ; and observations were 

 made on the result of difierent colours, the effects of mutual proximity, the 

 effects of illumination, and the times during which the larvte are sensitive ; 

 experiments on various parts of the body showed that the whole skin area 

 is susceptible. Further observations were made on V. Atalanta, Papilio 

 Machaon, Pieris brassicse and P. rajjse, Epliyra pendularia, and Saturnia 

 carpini ; the study of the last seems to show that the influence of the sur- 

 roundings can only be explained by the supposition of a complicated 

 physiological and aj)parently nervous circuit. 



Lepidopterous Larvae, Pupae, &c.t — Mr. E. B. Poulton after detailing 

 his observations on the larvae of Smerinthiis tilise and S.ocellatus and the red 

 spots in their larvae, as also on the markings of the adult larva of Ache- 

 rontia atropos, describes the markings aiding in the terrifying aspects 

 produced by the attitude of the larva of Cliserocampa Elpenor. The terrify- 

 ing attitude of the larva of Dicranura vinula produces an exaggerated 

 caricatui-e of a sort of generalized vertebrate appearance, e. g. a serpent, such 

 as would alarm small birds, and in this larva a fluid consisting of formic 

 acid is ejected from a gland, the duct of which opens below the head, 

 and so arranged that when the larva is disturbed, the fluid is directed 

 directly forwards. In I), furcula there is a green eversible gland occupying 

 the same position as this poison-gland, and the author considers this to be 

 a more primitive arrangement. The larva of Orgyia pudibunda has an 

 eversible gland situated in the median dorsal line of the seventh abdominal 

 segment, and evtrsion takes place when the larva rolls up. The larva of 

 Eemithea tlnjmiaria, in its normal attitude, has a very perfect resemblance 

 to a twig, owing to its head being notched, and to the presence of dorsal 

 tubercles. The early life of the larva of Acryonycta leporina is passed on 

 the lower side of the leaf of the alder or beech. It is concealed by its 

 long white hairs, but later on, when about to burrow in the bark, the hairs 

 become darker and thus render it less conspicuous. 



The apparatus by means of which imagines escape from the cocoon is 



* Proc. Roy. Soc, xlii. (1887) pp. 94-108. 



t Trans. Eutomol. Soc. Lond., 188(5, pp. 137-7y (1 fig.)- 



