=221. Advantages.= Both line and belt transects, after they have been recorded, should be rendered permanent, in order that they may serve to indicate the changes of a heterogeneous area from year to year in the same detailed fashion that the permanent quadrat does for homogeneous ones. For historical as well as for physical reasons, the ecotones of zones and of consocies are subject to change from year to year, and the amount and direction of this change can only be ascertained from annual records made in exactly the same spot. By means of the permanent transect alone the very origin of such areas can be followed from one stage to another of the succession. Moreover, the transect is equally valuable with the quadrat in making it possible to follow every step of the minute changes wrought by competition. =222. Details.= The transect is made permanent by blazing the landmarks at either end, if these already exist, or by erecting them when it is necessary. A label stake is driven at each end, on which is painted the number and date of the transect and its length. Each stake should also indicate the exact direction in which the other lies. The position of the ecotone is indicated by smaller stakes bearing the number of the transect and the date when the ecotone was found at that point. These are left in place, and in a few years show very graphically the change in position of the zones. For the first season, permanent transects afford results of great value when recorded for each aspect, but after this an annual visit will suffice. The details of mapping, plotting, etc., are identical with those indicated above, with the addition that all charts and photographs must bear the number of the reading as well as that of the transect. Physical factor observations are taken as often as the charts are made, and the results noted on the back of the chart sheet for purposes of ready comparison. _The Denuded Transect_