Note 2 — INTRODUCTION.
George Haslam translation
‘In animals with warm blood the action of the muscles is neither so apparent nor so long continued as in those animals which have cold blood, such as fishes and many other aquatic animals, and those also which live both in water and on dry land. On this account I have made my investigations chiefly on frogs, for in them the nerves are very distinct, and are easily found and exposed.’ Buch der Natur, Leipzig, 1752, p. 330.