84 THE entomologist's record. 



are also to be found in the other A cro?ij'ctas, and indeed in many 

 NocTUA (and other?) piipte, but are often so tine as to be 

 easily overlooked. 



EXPLANATION OF PLATE II. 



Natural Size.— Fig. I, — Pupa of Viminia niyrica:. 



Enlarged fF'ti- i^. — Pupa of V. myriccE ; dorsal view of anterior extremity, 

 about 8 -| Fig. lb. — Pupa of V. myriccc ; 9th segment, lateral view. 



diamettrs. \^Yig. ic. — Pupa of V. iityriccc ; lateral view of posterior extremity. 

 Natural Size.— Fig. 2. — Pupa of Viiniiiia nienyattthidis. 



Enlarged f Fig. 2a. — Pupa of V. vienyanthidis ; dorsal view of anterior extremity, 

 about 8 -)' Fig. 2b. — Pupa of V. vienyantliidis ; 9th segment, lateral view. 



diameters. L Fig. 2c. — Pupa of V. Vienyanthidis ; lateral view of posterior extremity. 

 Natural Size.— Fig. 3. — Pupa of Viminia venosa. 



r.nlarc'ed f Fig. 3a. — Pupa of V. venosa ; dorsal view of anterior extremity, 

 about 8 "! Fig. 3b. — Pupa of V. venosa ; 9th segment, lateral view. 



diameters. I Fig. 3c. — Pupa of V. ve:iosa ; lateral view of posterior extremity. 



Enlarged (^ Fig. 4a. — Pupa of V. rti7nicis ; dorsal view of anterior extremity. 



about 8 1 Fig. 4b. — Pupa of V. rutnicis ; 9th segment, lateral view. 



diameters, v Fig. 4c. — Pupa of V. riuiiicis ; lateral view of posterior extremity. 



MELANISM AND MELANOCHROISM IN BRITISH 

 LEPIDOPTERA. 



By J. \V. TUTT, F.E.S. 

 {Continued from page 56.) 

 DuT there is no doubt that another local condition, at least, 

 is brought into play in aiding " natural selection " in its work. 

 I refer to the presence of large wooded tracts in districts where 

 this artificial (so to speak) darkening of surfaces is occurring. 

 It is well known that large arid tracts of land in different parts 

 of the world have been planted with trees to increase the 

 water supply of such districts, and it is as well known that the 

 action of these trees on the atmosphere is such, that vast 

 quantities of vapour are condensed from it, and the atmosphere 

 in such a district becomes charged with moisture and very 

 different to its previous dry condition. It is also well known that 

 all large wooded areas have a moister atmosphere than areas 

 in immediate contact with them which are open in character. 

 Probably no trees have a tendency to hold so much moisture 

 as the different kinds of fir trees. I have long noticed this 

 tendency, and there is no doubt that the presence of moisture 

 in such localities, helps to make the natural dark colour of 

 these trees still darker ; add to this that fir trees, by means of 

 their foliage, shut out an immense proportion of light, and we 

 can readily understand that " natural selection," would leave, 

 to a great extent, only the darker insects in such situations. I 

 find it an actual fact in the south of England, that such localities 



