Öz The ventral head glands of the embryos of the gregarious and solitary phases of gregaria were examined histologically. l.Theyoriginateaspaired invaginationsfromthe epidermis justanteriortoand either side of the second maxillary segment in both phases just after revolution. They are lo- cated in a dorso-lateral position posterior to the dorsally situated primary head muscles and they curve downwards and backwards to a rejoin of the epidermis at a point oppo- site the sub-oesophageal ganglion.