house. The temperature changes in the two limbs, on their being moved in and out of the greenhouse, were noted for several days. The behavior was practically the same as when the limbs were attached to the tree. The dead limb was then soaked in water for some time and the temperature changes of the, two limbs again observed during both rising and falling temperatures.
   These observations show that the rise and fall of temperature of a dead limb is very appreciably checked on approaching the freezing point. In short, a soaked dead limb behaves like a live one, as far as temperature changes are concerned. There seemed also to be some indication that the temperature of the soaked dead limb, after having once passed below the freezing point, falls faster than that of the live limb below the same point. The later comparisons of the temperature changes of a live limb and a dead one not soaked are illustrated by the diagram for January 26, 1897. (Fig.3.) Alike comparison of alive limb and a soaked dead one is given by the diagram for February 26, 1897. (Fig 4.) In both these cases the limbs were placed out doors at 9 A. M. after having first acquired a uniform temperature in the greenhouse.

   Curve No. I shows the changes in the temperature of a thermometer in air.
   No. 2.--Temperature near surface of dead limb.
   No. 3.--Same at center of dead limb.
   No. 4.--Temperature near surface of live limb.
   No. 5.--Same at center of live limb.
   Limbs shaded till 1:15 P. M., in sunshine till 2 P. M. Sky cloudy remainder of day.

    No. 1 shows the temperature of air.
    No. 2 shows the temperature of surface of dead limb.
    No. 3 shows the temperature of center of dead limb.
    No. 4 shows the temperature of surface of live limb.
    No. 5 shows the temperature of center of live limb. Limbs shaded by a screen.

    No. 1 shows the temperature of air.
    No. 2 shows the temperature of surface of dead limb.
    No. 3 shows the temperature of center of dead limb.

   No. 4 shows the temperature of surface of live limb.
   No. 5 shows the temperature of center of' live limb.
   Limbs placed outdoors at 9 A. M.

   No. I shows the temperature of air.
   No. 2 shows the temperature of surface of soaked dead limb.
   No. 3 shows the temperature of center of soaked dead limb.
   No. 4 shows the temperature of surface of live limb.
   No. 5 shows the temperature of center of live limb.
   Limbs placed outdoors at 9 A. M.

   Few matters are of greater economic importance than that of how and to what extent the seeds of flowering plants are distributed by winds. To the ecologist and phyto-geographer it is one of no moderate interest, as geographical distribution, though local, is in each of these lines of modern research no inconspicuous part; to the student of local florae it accounts partially for the unexpected appearance of species whose natural habitat has been assigned remote from his district of special work; while to the agriculturist it affects vitally his success or failure on the farm.
   No available data touching directly upon the subject have been tabulated; perhaps none have been collected. Under my direction the students of the Franklin High School have carried forward for the past three years a series of field collections and laboratory cultures that have opened the problem at least to wider investigation. Our work briefly is thus:
   We have made exposures of collecting traps in the various situations afforded us on the high school campus, around the homes of the students, and in the open prairies and fields. Leeward and windward positions were selected when previous indications foretold the direction of the wind; the value of these different positions is apparent from the widely different results obtained thus from the same period of observation. The different situations., as campus, barnyard, prairie, ravine, field, etc., give lawful variations which the observer can easily account for.
   The traps used were deep tin cans, anchored fast by means of stout stakes to which the cans were securely wired in a manner allowing of easy detachment to remove the contents. Winds were grossly classified into four groups: breezes, local winds,

high winds, and continued gales; such grouping being based upon the force and continuance of atmospheric movement. The trash and dust were carefully removed from the cans and labeled as to location, date, length and strength of wind. A specimen label is as follows:
   "Harry Davis; open pasture south of Franklin, one-half mile from tilled soil; continued gale, two days; Oct. 10-11, 1894."
   In many instances dates were not recorded, but the general season-period is known. These omissions have so affected the calculations that no definite dates can be given in the tabulation; the early or late season-period, however, is fairly accurate.
   Vegetable mould, calorized to prevent extraneous growths, was added to the collections and under fair conditions the seeds contained therein were germinated. Many of the plants grew to maturity, others developed sufficiently to reveal their identity, a few were classed "unknown."' The tabulation of results is not as satisfactory as could be wished, but it suffices to show the general trend of the investigation.
   The. following table shows calculations obtained from forty-eight collections, 1893-4-5-6, taken during

   A single series of experiments can give no well-founded results, and may vary widely from the truth; however, in general it is noticed that breezes and local winds do not distribute ordinary plant seeds over very great areas, while oppositely, high winds and continued gales scatter the seeds widely over pasture and meadow, hill, ravine, field, and prairie alike.
   It is at once noticed in the above table that the comose seeds, and the pappose and chaffy seed-bearing fruits are dislodged and scattered by the early fall breezes, the seeds of the Compositae and the Asclepeidaceae predominating in numbers. The local winds bear, besides comose and pappose seeds, those of the Cheopodiaceae and Amarantaceae, whose presence is very undesirable economically. High winds do not, as many may suppose, bear the lighter comose, pappose, and membranaceous seeds in greater numbers than does it of those of denser structure. Though the high winds are far more than any others, the seed carriers, they are also the atmospheric agents that loosen and drift forward many seeds that are too heavy to be borne within itself above the soil surface. The cultures of material collected during continued gales gave very disappointing results. Our adventive, newly introduced, and "out-of-range" species have come within out-boundaries by the steady monsonic gales so prevalent from the north and south, over the plain district of Nebraska, Kansas, and the Dakotas. The alarming invasion of the "Russian thistle," Salsola tragus L., in 1894-5, the appearance of carpet weed, Mollugo verticillata L., throughout the entire county (Franklin) in 1892, and the occasional growths of wild carrot., Daucus carrota L.,, are to be attributed to these continued gales.
   A reference to each of the other tables in the series may not be amiss:
   1. The October collections gave 20% more of Compositae, 8% more of Asclepeidaceae, and a considerable gain generally in the lighter seeds, especially those adapted to aerial carriage; arousing a strong suspicion, which other conditions tend to verify that October is predominantly the month of local distribution.

Gramineae, Amarantaceae, and Chenopodiaceae each gain from 1 to 3% when dynamic data are unchanged.
   2. The November collections were notable for a great increase in the Chenopods and Amaranths. These grow mainly in fields, and ripen early and late. The increase of distribution of seeds is probably accounted for by this being the mouth of corn-gathering and stalk-pasturing on the farms. Ofttimes steady winds prevail during the entire mouth. These two conditions uniting, the tendency is toward a wider and easier dispersion and dissemination than during any other month of the year.
   3. December and January show very light movements of seeds, these being buried beneath snow and frozen fast to the surface. Hence these months are periods of little importance in the matter under discussion. Lower latitudes would give data of interest.
   4. February and March are also inactive periods. Collections were abundant in debris, but careful cultures showed that very few seeds likely to germinate were contained therein. The reasons are too obvious to necessitate mention.
   5. April is the month of active spring work and coupled with it are our spring monsoons. Operating together, no light effect in distribution is noticed. In fact., all things loose tend to fly to the uttermost parts of the earth. Among the commoner ones, seeds of Garden Purslane, Portulaca oleracea L., Tansy Mustard, Sisymbrium canescens Nutt., Black Mustard, Brassica nigra (L.) Koch., Wild Pea, Astragalus gracilis Nutt., and Winged Dock, Rumex venosus Pursh., were unexpectedly present and their prominence in the culture growths showed them to be in prime condition. A few early cottonwoods and willows appeared also.
   It will be noticed that these data and compilations are in reference to horizontal variations only. Though it may prove an error, still it is the popular belief that the wind distribution of seeds takes place within that stratum of air that lies about thirty or forty feet from the earth's surface. Let us hope that investigations may soon give us data as to vertical variation, that we may know more fully the importance and service of fences, wind

breaks, weather-growths, and hedges toward hindrance and possible barriers of seed dispersion and dissemination. The old adage: "An ounce of prevention is better than a pound of cure" is pertinent to this matter.
   [NOTE.--The term "seed" in this paper applies to the general non-technical use of the word rather than in a strictly botanical sense. it often implies those organs technically called fruit cluster and fruit. E. M. H.]

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