Part 3 (1/2)

NUMBER 4 P.M. 6 P.M. 8 P.M.

OF ANIMAL RIGHT LEFT RIGHT LEFT RIGHT LEFT

29 33 114 31 36 45 99 33 436 7 408 3 364 2 35 279 6 165 24 353 10 151 3 8 2 285 2 217 157 52 15 19 125 51 104 211 190 7 86 31 67 250 215 15 292 45 336 150 232 225 133 86 48 39 177 81 415 268 3 437 7 382 8 425 12 242 19 210 4 192

Averages 142.1 78.0 126.0 109.6 159.5 119.5

Gen. Av. 220.1 235.6 279.0

The most important results of this statistical study of turning are the demonstration of the existence of individual tendencies to turn in a particular direction, and of the fact that the whirling increases in amount from morning to evening.

In order to discover whether the distribution of the dancers among the three groups which have been designated as right, left, and mixed whirlers agrees in general with that indicated by Table 4 (approximately the same number in each group) I have observed the direction of turning in the case of one hundred dancers, including those of the foregoing tables, and have cla.s.sified them in accordance with their behavior as is indicated below.

RIGHT LEFT MIXED WHIRLERS WHIRLERS WHIRLERS

Males 19 19 12 Females 12 23 15

Totals 31 42 27

The left whirlers occur in excess of both the right and the mixed whirlers. This fact, together with the results which have already been considered in connection with the counts of turning, suggests that a tendency to whirl in a certain way may be inherited. I have examined my data and conducted breeding experiments for the purpose of ascertaining whether this is true. But as the results of this part of the investigation more properly belong in a special chapter on the inheritance of behavior (XVIII), the discussion of the subject may be closed for the present with the statement that the preponderance of left whirlers indicated above is due to a strong tendency to turn to the left which was exhibited by the individuals of one line of descent.

TABLE 4

AVERAGE NUMBER OF WHIRLS TO THE RIGHT AND TO THE LEFT FOR THE SIX INTERVALS OF TABLES 2 AND 3, WITH A CHARACTERIZATION OF THE ANIMALS AS RIGHT WHIRLERS, LEFT WHIRLERS, OR MIXED WHIRLERS.

AVERAGE NO. AVERAGE NO.

MALES AGE OF WHIRLS OF WHIRLS CHARACTERIZATION

2 12 mo. 136.7 3.3 Right whirler 30 2 mo. 109.7 2.5 Right whirler 34 2 mo. 4.3 96.5 Left whirler 36 2 mo. 197.5 23.5 Right whirler 152 6 mo. 6.8 137.0 Left whirler 156 1 mo. 73.2 12.8 Right whirler 210 3 mo. 78.7 62.0 Mixed whirler 220 4 mo. 74.3 40.2 Mixed whirler 410 3 mo. 10.3 139.0 Left whirler 420 3 mo. 12.2 241.3 Left whirler

Average 70.4 75.8 4 Right whirlers 4 Left whirlers 2 Mixed whirlers

FEMALES

29 2 mo. 23.7 53.2 Left whirler 33 2 mo. 362.7 2.7 Right whirler 35 2 mo. 208.5 19.2 Left whirler 151 6 mo. 5.0 140.0 Right whirler 157 1 mo. 47.0 51.2 Left whirler 211 3 mo. 109.7 61.5 Right whirler 215 3 mo. 57.8 234.5 Mixed whirler 225 4 mo. 103.2 56.3 Mixed whirler 415 3 mo. 216.7 3.5 Left whirler 425 3 mo. 17.0 225.2 Left whirler

Average 115.1 84.7 3 Right whirlers 4 Left whirlers 3 Mixed whirlers

The tendency of the dancer's activity to increase in amount toward evening, which the results of Tables 2, 3, and 4 exhibit, demands further consideration. Haacke (7 p. 337) and Kis.h.i.+ (21 p. 458) agree that the dancing is most vigorous in the evening; but Alexander and Kreidl (i p.

544) a.s.sert, on the contrary, that the whirling of the individuals which they observed bore no definite relation to the time of day and apparently was not influenced in intensity thereby. Since the results of my own observations contradict many of the statements made by the latter authors, I suspect that they may not have watched their animals long enough to discover the truth. The systematic records which I have kept indicate that the mice remain quietly in their nests during the greater part of the day, unless they are disturbed or come out to obtain food. Toward dusk they emerge and dance with varying intensity for several hours. I have seldom discovered one of them outside the nest between midnight and daylight. The period of greatest activity is between 5 and 10 o'clock P.M.

Zoth states that he has observed the adult dancer whirl 79 times without an instant's interruption, and I have counted as many as 110 whirls. It seems rather absurd to say that an animal which can do this is weak.