Fig 3. Experiment 136, illustrating Type III, in a case where the asymmetry passes over directly into regular response away from the side touched, but with a long interval. 31 3.13 32 47 ora 3347 C 38 28 C 39 28 403:33 C2 41 43 42 29 08 43 541 C 44 262 450:51 46 30 FIG 2. Experiment 151, illustrating Type II. FIG. 4. Experiment 37, illustrating Type III, in a case where asymmetry in response passes abruptly into regularity, and the asymmetry is preceded by two movements at variance with it. 5. (Upper figure.) Experiment 48, illustrating Type III, in a case where the period of irregularity is influenced, apparently, by the preceding asymmetry. It should be observed that the reactions were taken rapidly during the period of asymmetry and irregularity. FIG. 6. (Lower figure.) Experiment 162. The embryo from which this. record was made was, on the whole, the most irregular specimen of my series. Still, after the period af asymmetry there is a marked general tendency to move the head away from the side touched. For further data see Table, p. 92. *The first 30 responses, distributed through 23 hours and 13 minutes, were all directed away from the side touched. During one period of 41 hours and 31 minutes there were 30 consecutive responses away from the side touched. During one period of 46 hours and 13 minutes there were 22 consecutive responses directed away from the side touched. || During one period of 57 hours and 36 minutes there were 25 successive responses directed away from the side touched. § During one period of 36 hours and 50 minutes there were 18 successive reactions directed away from the side touched. **During one period of 41 hours and 32 minutes there were 19 successive responses directed away from the side touched. tt During one period of 47 hours and 6 minutes there were 25 successive reactions directed away from the side touched. During one period of 22 hours and 59 minutes there were 17 successive movements directed away from the side touched. §§ There were in all 52 responses, distributed through a period of 137 hours and 33 minutes. Of these responses, 40 were directed away from the side touched, a percentage of 76.9. TYPE III. TYPE I. Column G. The time during which the embryo is considered as moving its head regularly away from the side touched. Column H. The number of responses given during the period represented by Column G. Column I. The percentage of the responses indicated in Column H that were away from the side touched. The time is recorded in each instance in hours and minutes, excepting in a few instances in Column B where the time was not determined. Averages are given in the several columns for each of the three types, excepting in Column H where the corresponding numbers represent totals. With reference to the side touched in each trial my records are complete, but, inasmuch as the records in Column G clearly have no references to the side touched as determining factor, this element of the question is omitted from the table. A comparison of the averages in Column B of the table might be interpreted to mean that the specimens of the second and third type came under observation relatively earlier in the period of development than did the specimens of the first type. But it should be noted that the figures in Column B represent the maximum possible time of irritability before the observation of it began. On the other hand, a comparison of the averages in Column G shows a clear distinction between Type I, on the one hand, and Types II and III, on the other. There is a difference of, say, 10 to 15 hours in the length of the period of regularity in moving the head away from the side touched. Furthermore, if the average of Column G for Type I be compared with the corresponding average for Type II plus the averages of Column E and F of this type, it will be seen that the embryos of Type I were longer in passing through the one period of regularity than were the embryos of Type II in passing through the periods of both regularity and irregularity, including the interval. It would seem, therefore, that a period of irregularity has not been passed over unobserved in Type I, and that the distinction between these two types is not based on the relative age of the individuals when they came under observations. A similar comparison of the corresponding figures for Type III with those of Type I shows that the time represented by Columns E, F and G for Type III approximately equal that of Column G for Type I. But for the excessively long period of No. 38 in Column G, the comparison would result about the same as that |