AL 129-1 a monkey, and decided to collect it. While he was writing it up, he noticed a few yards away a distal femur, the lower end of a thighbone. This was split between the condyles, or lumps making the knee joint. The other condyle lay next to it, and when he fitted them together and to the proximal tibia, the angle that the femur and tibia formed at the knee joint clearly showed that this was an upright walking hominid. This angular joint was in contrast to an ape, which has the femur and tibia forming a straight line. Tom Gray
Tibia Clausa alternate name for Doppelflöte. Most tibias are made from wood, as by Wurlitzer etc., although examples of metal tibias may be found made by the John Compton Organ Company. The Tibia Clausa, or Tibia, is generally found at 16′, 8′, 4′ and 2′ pitches as a unified rank. The mutation ranks Tibia Quint 5⅓′, Twelfth 2⅔′ and Tierce 1′ are also drawn from this unified rank of 97 pipes. In some larger organs, a second Tibia rank may be present, extended to 1′ instead of 16′, allowing a 1⅓′ Nineteenth mutation and a 1′ Piccolo to be drawn from this