ENTOMOLOGY

884 SANITARY ENTOMOLOGYAfter the young had developed for several days and were sufficientlylarge to handle readily, they were placed upon the escutcheon of a cowthat had been inspected thoroughly and found free from lice. Other licewere left on the calf. In a given number of days eggs could be foundon both the calf and on the escutcheon of the cow. These eggs wereagain watched until they hatched and in thiE way the periods of timewere recorded, and checked often enough to be reasonably sure of theaccuracy of the results.With the biting lice the work was much mo.re difficult because thesedo not remain in one place. Celluloid caps, somewhat like those used forprotecting vaccination points, were used to contine the lice. Areas wereshaved leaving small tufts of hair on which the lice could breed, andadhesive tape bound the caps to the calf. 'l'he electric incubator kept atthe approximate temperature of the cow's skin was used to supplementthe observations made on the animal itself.CONTROL MEASURESA control measure or remedy for cattle lice, in order to be practical,must be cheap, reasonably easy to apply, effective in killing the lice, andat the same time do no injury to the cow. It should not be so poisonousthat the accidental consumption by animals would endanger their life.At the same time the material used for control should be commonly sold,and thus be within the reach of purchasers even in the remoter countryvillages.Clipping.-Clipping the stock over the portion of the animal mostlikely to be infested is not an uncommon practice, and, where the hairis long and the animal is very badly infested, it helps to bring the oilor wash where it will be most effective. We have found, however, thatanimals that have been clipped are more liable to show a considerablescurting of the skin because the application reaches the skin more quicklyand in larger quantities than when it is held on the hair and thus reachesthe skin gradually. There are those who feel that .the animals do notlook as well when clipped.If control measures are used early, thoroughly, and repeated throughoutthe winter, clipping will be unnecessary.OILSRaw Lmseed Oil.-Of the many difFerent measures for the control oflice on dairy cows and young stock, raw linseed oil gave the best resultsfrom the standpoint of economy of material and labor of application,killing the lice, but not injuring the skin, and at the same time not