ENTOMOLOGY

LICE WHICH AFFECT DO}IESTIC ANDIALSthat will not cause a slight degree of scurfiness on the cows at times. Ifone will look at 0. condition of scurfiness carefully he will find that looseportions of the epidermis have lifted, and fragments are thick in thehairs, yet there is no irritation or reddening of the tissues and hence noreal injury. Scurfiness is a condition that may occur without any applicationto the skin and it should not deter the dairyman from using a controlmeasure that does not cause a real injury. Scurfiness passes in ashort time and leaves the skin clean underneath.,SS9Part~.Lice Affecting Chickens, Hogs, Goats, Sheep, Horses, andOther AnimalsF. C. BishoppThe habits and control of lice on cattle have been discussed in anotherlecture. Owing to the marked economic importance of lice on otheranimals, the diversity of their habits and the great difference in themethods of handling the hosts, an additional lecture is devoted to thesubject.LICE INFESTING DOMESTIC FOWLSFowls are infested with biting lice (order Mallophaga) only. Thereare a large number of species living on the various domestic fowls. Thechicken is infested with about ten species (seven of these commonly), theturkey with four, the pigeon with eight (three commonly), the duck five,the goose seven, the guinea fowl six, and the peafowl four.Of course in listing the number of lice on the different hosts enumeratedthere is some duplication. We find that under certain conditionschicken lice are to be found on several of the other domestic fowls andthis is true to some extent with forms which are found on other species.There are a number of factors which influence the transference of anyof these parasites from their normal hosts. Ordinarily most of themare quite closely restricted to one species of fowl and the habits of thelouse and the host are so interrelated that it is doubtful if many ofthem will continue to hreed successfully on strange hosts, although ofcourse they may be harbored for a time. When several species of fowlsare closely associated, especially on roosts, there is tl considerable chancefor the interchange of the different species of .parasites and we can notalways say that when a given species is found on an unusual host it.will succeed in establishing itself and breeding thereon. Furthermore wehave observed that the young of a species seems to be attacked by asmaller number of species than the adult fowls. In fact some of thespecies of lice most commonly found on adults do not seem capable of