EDWAEDSIA W- ALBUM. 167 



green in the interspaces of the segments ; the ventral area is also 

 greenish ; on each side of each segment are two oblique and very ill- 

 defined stripes of a paler shade, and, when the larva is at rest, the upper 

 of these meets the lower one on the next following segment, thus 

 producing the appearance of its having eight oblique stripes on each 

 side; the legs and claspers are pale dingy green, obscurely diaphanous 

 (Newman). 



Variation in larva. — The larvae usually appear to be bright green 

 until the penultimate instar, then bright green or yellowish-green, with 

 occasional rufous points in the penultimate instar, finally becoming 

 somewhat variable in the final instar. Of eight larvae under observa- 

 tion (June 1st, 1905) no two are exactly alike. Shortly, the more 

 marked forms may be noted as follows : 



(1) Ground colour bright green ; the raised points of the double dorsal ridge, 

 the lateral flange, and oblique lateral stripes of a pale yellowish tint (making the 

 ground colour itself appear as dark lateral stripes between the true pale lateral 

 stripes, to the naked eye) ; the median area, in the depression between the dorsal 

 ridges, -and its extensions anteriorly and posteriorly, of a dark sap green, with a 

 pale, narrow, mediodorsal line traversing it on abdominal segments 1-6 ; the lateral 

 flange slightly tinged with reddish on the 6th, 7th, and 8th abdominal segments. 



(2) Ground colour rather paler green than in 1 ; the projecting points of dorsal 

 ridges, of lateral flange, and lateral oblique stripes pale whitish- (rather than 

 yellowish-) green ; the median area between the dorsal ridges, and its extensions in 

 both directions, of a deep chocolate-red with a narrow green mediodorsal line (on 

 abdominal segments 1-6, where the dark markings take the form of chevrons) ; 

 lateral flange tinged with red on the 6th and 7th abdominal segments. 



(3) Ground colour green, the projecting points of the dorsal ridges and the lateral 

 oblique stripes red-brown, edged throughout with yellow ; the lateral flange almost 

 crimson in tint ; the median area between the dorsal ridges, and its extensions in 

 both directions, dark red-brown, with a faint yellow mediodorsal line from abdominal 

 segments 1-3 ; the prothorax reddish ; the anal segment green, divided medially by 

 the dark median line. 



(4) Groimd colour yellow-green ; the sides made up of alternate streaks of 

 reddish (which seem to be overlying the green groimd) and yellow ; the tips of the 

 dorsal ridges yellowish ; the median area between the dorsal ridges and its extensions 

 reddish-brown, with a paler thin rufous median line ; the lateral flange yellowish, 

 overlaid with red ; the anal flap yellowish-green, with a very dark extension of red 

 median series traversing it. 



(5) The yellow-green ground colour almost entirely masked by a bright red 

 tint, which alternates with the pale yellow-green oblique lateral lines, occupies the 

 prominent parts of the dorsal ridges, fills in the depression between the dorsal 

 ridges, and quite covers the lateral flange, and some little distance above and below 

 it ; the median line (of chevrons and continued lines forward and backward) very 

 bright red-brown. Except for the anal flap and segmental incisions laterally, there 

 is little distinct evidence of the ground colour. The outside of prolegs is tinted 

 (also in the other forms) similarly to the lateral flange, i.e., of a rather more rosy or 

 crimson tint than the other red markings. 



COLOUE CHANGE OF LAEVA DURING EESTING-PEEIOD PEECEDING 



pupation. — Reaumur first noticed (Mem., i., p. 450) the change 

 in the colour of the larva of this species before pupation. Crewe 

 says that the larva of this insect entirely changes colour a day 

 or two before spinning up, losing its beautiful primrose tint and 

 becoming reddish-brown. This is only partly true, for, although 

 the larvae all change colour, there is considerable difference in the tint 

 that accompanies the darkening. The two commonest forms of larva — 

 (1) yellow-green, (2) bright grass-green — appear to undergo quite 

 different colour-changes in the resting-period preceding pupation. The 

 following notes may prove interesting: 



