Figure 4.

Frequency plots of the proportion of slow fibres in the three lumbar muscle tracts studied: (a) dorsomedial, (b) dorsolateral, (c) ventral of the mouse lemur (M), brown lemur (E), gibbon (G), orangutan (O), bonobo (B) and the three chimpanzees (C1, C2, C3) (from top to bottom). The proportions of slow fibres were divided into classes of 10% for each lumbar level and the frequency of their occurrence in a given tract and level was plotted. Numbers in the top right corner of each graph represent means ± SD (first line) as well as minimum and maximum (second line) of the slow fibre proportions observed at the respective vertebral level. Numbers to the left of each row indicate mean ± SD of the percentage of slow fibres for all lumbar levels investigated.