CoGHiLL, TJie Reaction to Tactile Stimuli. 93 



The several eolunins in this talnilation have significanee as follows : 



Column A. The number of the experiment, the data of which 

 read to the right. 



Column B. The time that elapsed between the last trial which 

 gave no response and the first to which response occurred. 



Column C. The time during which the embryo was asymmetri- 

 cal in response. 



Column D. The interval or time that elapsed between the last 

 observed response that accorded w^ith asymmetry and the first re- 

 sponse that accorded with irregularity. 



Column E. This is the second phase in the development of em- 

 bryos of Type III, and the first phase of embryos of Type II. It is 

 described above as the period of irregularity in response. 



Column F. The interval or time that elapsed between the last 

 observed reaction that accorded with irregularity and the first that 

 accorded with the regular form of response as described above for 

 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, ex- 

 cepting in a few instances in C^olumn B where the time was not 

 determined. Averages are given in the several columns for each of 

 the three types, excepting in Colunni IT w^here 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 develop- 

 ment than did the specimens of the first type. But it should be 



