Keywords: Life in Motion Fig 41.png en Fig 41 ”Drop of human blood a coloured or red corpuscle showing clear spot in centre or a ˛ dark spot in centre according to focus; b b b colourless corpuscles or leucocytes; b ˛ red corpuscles in rouleaux 300 diameters Life in Motion or Muscle and Nervehttps //archive org/details/b21929786 John Gray McKendrick 1892 1926 Life in Motion book Blood cells |