196 MR. E. B. POULTON ON THE PROTECTIVE [Mar. 1, 



by the Frogs, and probably in the case of the Spiders also (in fact, 

 Mr. Butler states that tliis was the case), but a bite from a Lizard 

 ■would always be very serious and generally fatal. Mr. Butler states 

 that the Lizards seized the distasteful larvae before rejecting them, 

 although this may not have been in many instances. Mr. Butler 

 has kindly given me an account of some further experiments upon 

 birds, the results of wliich are included in the Tables below. 



Professor Weismann (' Studies in the Tlieoryof Descent,' Part IL, 

 pp. 336-340, English translation by Prof. Meldola) also experimented 

 with Lacerta viridis, with the results that the following brightly 

 coloured distasteful larvae were refused : — Clisiocnmpa neustria, 

 Euchelia Jacob cecB, PygcBra bucephala, Pieris brassicce, Deilephila 

 gain. On the other hand, the very highly conspicuous larvae of 

 Deilephila evphorhifB were eaten, as also were those of E. lanestris 

 and Lusiocampa pini. The young larvae of Lasiocampa rubi, at a 

 stage when they much resembled those of the rejected E. jacobfefS, 

 were eaten after cautious examination. Professor Weis.nann also 

 regarded the larva of Papil.io machaon (always rejected) as conspi- 

 cuous ; but from my own experience I should ceitaiiily consider it «ell 

 concealed upon its food-plant, and I sliould exchide it from the cate- 

 gorv of conspicuous larvae wliifh support Wallace's sugvce>tion. 



Mv own experiments were conducted with green Tree- Frogs {Hi/la 

 arborea, var. merii/ionalis), and with Lizards of the followmg spe- 

 cies: — Laceita viridis, L. murulis (chiefly var. tiliyuertd), and Taren- 

 tola mavritanica. 



My diary, printed in the form of Appendix IL to this paper, will 

 give all the details, dates, &c. of the various experiments made 

 during the summer of ibSG, so that it is unnecessary to further 

 allude to them here. 



Finally, when a few weeks ago I told Mr. Jenner Weir of my 

 intention to bring totrethcr all the experimental evidence upon this 

 subji'Ct, he most kindly sent me the notes of his own observations 

 durnig li^8f3, for incorporation in this paper. His ex[ieriirients were 

 conducted wi'li tlie following species ot Lizards: — Lacerta viridis, 

 L. Off His, and Zootoca vivipara, and the diary is also piinted in tull 

 as A|)pendix 1. 



It now remains to tabulate the results of all the experimental 

 evidence upon cons|)icuous larvae detailed above or desc i led in the 

 Apiiendices. Before doing so, it is necessary to recall Walbtce's 

 original suggestion, " that brilliant or cons|)iciious larvae would be 

 found to be refused by their enemies : " that is to say, they wdl be 

 found to possess some unpleasant attribute. Tiiis may be a dis- 

 agreeable taste or a nauseous sniell in the fluids and tissues of the 

 larva, and perceived alter it has been bitten ; or it may be a strongly 

 smelling fluid, discharged by certain speciid glands on the approach 

 of an enemy (e. g. Porthesia aurijiua with dorsal glands, or the 

 Hymenopterous Croesus septentrionulis with ventral glands ; in both 

 these cases the smell given oft' from the everted glands can be readily 

 perceived as sharp or unpleasant to ourselves). Tiie larvae of Pieris 

 brassiccE, or of Pygcera bucephala, &c., form instances of the former 



