1. Baborovski, Velisch and Wagner (1928).J. Chim. Phys., xxv, 452.
2. Bear and Schmitt (1939).J. Cell. & Comp. Physiol., 14, 205.
3. Bourbion, Ronyer and Hun (1937).C. rend. Acad. Sc., cciv, p. 1420.
4. Boyle and Conway (1941).J. Physiol, 100, 1.
5. Brandt (1945).Acta physiol. Scand., Vol. 10, Supp. xxx.