Normal values have been established for the activity of glyceraldehyde-phosphate
dehydrogenase and glucose-6-phosphate dehydrogenase in the erythrocytes of sheep
maintained under experimental and field conditions in South Africa. The 10 per
cent lower, 80 per cent and 10 per cent upper limits have been established for the
former enzyme as 400- 424, 425-730 and 731-900 micrograms/ml of blood respectively.
Negligible activity of the latter enzyme has been demonstrated in the ovine erythrocyte
by three different methods. Glycolysis in the red blood cells of the sheep is believed
to proceed mainly via the direct Embden-Meyerhof pathway. The importance of
these findings with regard to the ovine disease syndromes, geeldikkop and enzootic
icterus, is mentioned.