The physiology of digestion in the larvae of the horse bot-fly,Gasterophilus intestinalis(de Geer)

Evidence is produced to show that the larvae ofGasterophilus intestinalisare occasional blood feeders but normally feed on tissue exudate. 2. The demonstration, by Roy (1937), of the following enzymes has been confirmed and curves of their activity at different hydrogen-ion concentrations have been constructed: mid-gut amylase, proteinase and lipase. 3. The following enzymes have been demonstrated and curves of their activity at different hydrogen-ion concentrations have been obtained: maltase, invertase, polypeptidase and di-peptidase of the mid-gut and amylase, maltase and invertase of the salivary glands. 4. The haemolymph was shown to contain a lipase as well as an amylase and an anticoagulin.