The House Fly

abdomen anterior appear attached bacillus bacteria body breeding canicularis carried carriers caught cells cent cephalic common containing covered crop cultures deposited described diarrhoea discs disease dissemination domestica dorsal duct eggs enteric evidence examined excrement experiments fact faeces feeding female fever flies four frequently further ganglion given gives glands habits head Health house-fly houses important indicate infection interesting internal intestine Journ larvae lateral legs length male manure marked material means median milk Musca muscles nature nerves observations obtained occurred oral lobes organisms pair parasitic period pharyngeal plates portion possible posterior present probably proboscis processes pupae records reference region relation Report retractor sclerite seen segment shown side similar situated species spiracle stage structure summer supply surface temperature thoracic tracheal typhoid usually ventral wings