BREEDING HABITS OF HETERONEREIS. 157 



preted to mean that completely metamorphosed animals usually 

 do not occur during this time. 



6. July, 1912; curve 7. The run began on the ninth day after 

 the first quarter of the moon, on the night of the full moon (June 

 29). This run shows no evidence of two modes, for the lack of 

 animals on the second night of the run cannot be interpreted 

 as the intermodal depression. The run continued until the 27th 

 day. The absence of two modes in this case may be attributed 

 to overlapping of the two sub-runs making up each run. This 

 run was followed by eight days without any swarms. The 

 August, 1912, run, already described, finished on the 26th day 

 after the first quarter; and there was an interval of eleven days 

 before the beginning of the September run. 



7. September, 1912; curve 8. This run began on the eighth 

 day after the first quarter of the moon, and ended unusually 

 early on the 23d day. Though the curve is irregular in its first 

 part there is some evidence of bimodality. 



The tw r o features that stand out most prominently in these 

 records are the relation of the runs to the lunar cycles, and the 

 double character of each run. The following tabulation brings 

 out the first point; the days being numbered from the first 

 quarter of the moon in each case: 



1911. First run, tenth to twenty-eighth day. 

 Second run, ninth to twenty-sixth day. 

 Third run, eighth to twenty-sixth day. 

 Fourth run, thirteenth to twenty-first day. 



1912. First run, thirteenth to thirty-fourth day. 

 Second run, ninth to twenty-seventh day. 

 Third run, fifth to twenty-sixth day. 

 Fourth run, eighth to twenty-third day. 



As regards the second point, the curves show sufficiently well 

 that each run is made up of two sub-runs. But they are not 

 usually sharply separated by an interval as in the case of the 

 main runs; however, the general rule is that the interval occurs 

 near the time of the third quarter of the moon. Thus the low 

 points in the runs as tabulated are: 



ign. Days after First Quarter. 



First run. ... . 20 



Second run 17-21 



Third run 1 7 



Fourth run. 15-21 



