Fig. 4. (A) Mean combined length of the tarsus and tibia in chicks between ED11 and ED18. ^**P<0.05, ^***P<0.001. Sample sizes: ED11, N=14; ED12, N=16; ED15, N=32; ED18, N=24. (B) Mean femur length between ED12 and ED18. Sample sizes: ED12, N=16; ED15, N=28; ED18, N=22. ^**P<0.05, ^***P<0.001. (C,D) Alcian Blue/Alizarin Red-stained chick hind limbs; red staining shows mineralized bone, while blue staining shows the unmineralized cartilage. (C) Representative hind limbs at ED12; the top limb comes from a chick raised at 38.5°C while the lower limb comes from a control chick. (D) Representative hind limbs at ED15; the limb on the left comes from a chick raised at 38.5°C, with a control limb on the right. Scale bar in C and D represents 5 mm. Sample sizes were ED12, N=12; ED15, N=22. (E,F) Images taken from Micro-CT scans of ED15 femurs. (E) ED15 femur of a chick raised at 37.5°C; left image shows the whole bone while the three right images show, top to bottom, individual scans at 25%, 50% and 75% length of the mineralized portion of the bone (as calculated by the programme); the white portion in the cross-sectional scan represents mineralized bone. (F) As E but for a chick raised on the experimental temperature regime.