“…It is this aspect of the question to which most of our results are relevant, but the experiments were originally planned in the hope of deciding a different point, namely, whether contraction bands are formed, and, if so, under what conditions. The formation of contraction bands, and the consequent reversal of striations, was seen by many observers during the second half of the 19th century (see review by Heidenhain, 1899); this was confirmed by some more recent workers (Jordan, 1933;Speidel, 1939), but denied by others (Hiirthle, 1909;Buchthal et al 1936). Even if the reality of these contraction bands was admitted on this evidence, there remained the question whether their formation was an accompaniment of 'activation', of tension development or of shortening; this distinction could not be made on the existing evidence, since only slow contractions, with more or less unlimited shortening, had been studied.…”