Fig. 5. (A) Mean number of myofibres and myonuclei per 150 000 µm² of cross-sectional area of the gastrocnemius muscle at ED18 (N=14). (B) Mean mass of the gastrocnemius at ED18 (N=14). (C) Mean ratio of myonuclei:myofibre in the gastrocnemius at ED18 (N=14). In A–C, ^**P<0.05, ^***P<0.001. (D,E) Representative haematoxylin- and eosin-stained cross sections through the gastrocnemius of ED18 chicks raised at 37.5°C (D) and 38.5°C (E). Scale bars, 50 µm. (F,G) Representative Decorin antibody stained cross sections, through the gastrocnemius at ED18 of chicks raised at 37.5°C (F) and 38.5°C (G).