Succinic Acid in the Blood of the Larva of Gastrophilus intestinalis

DURING the course of biochemical investigations on the parasitic larvæ of the fly Gastrophilus intestinalis, advantage was taken of the ease with which the hæmoglobin-containing `tracheal organ' cells¹ and the hæmolymph which surrounds them could be obtained in order to study the interrelationship between the two in vitro. For this purpose an investigation of the respiratory metabolism of the tracheal organ was undertaken, employing standard manometric methods.