80 University of California Publications in Zoology [Vol. 19 



There is some similar evidence in Calanus; but under the experi- 

 mental conditions it accounts for the vertical movement of only about 

 20 per cent of all individuals. Whether this factor will appear in other 

 species remains to be ascertained; but it may be of general occurrence 

 and importance in connection with the diurnal movement. 



7. While special attention was not given to the study of individual 

 differences in behavior, the work with single animals has suggested 

 that sooner or later experimental zoology may well be definitely con- 

 cerned with the peculiarities that appear in different individuals of a 

 species, even when all specimens are kept under the same conditions. 

 Individuality manifested itself everywhere, and I believe that there is 

 a fruitful field for study along that line. 



In conclusion it is a pleasure to speak of the suggestions and 

 assistance received from the resident staff at La Jolla. The seminars 

 afforded opportunity for discussion, and there were besides many 

 stimulating conversations. Mr. E. L. Michael was unsparing of his 

 time in talking over matters connected with presenting the experi- 

 mental data, especially as to arrangement in tabular form that will 

 permit of testing probability by statistical methods. Professor Ritter 

 was always ready to listen and advise, and Mr. W. C. Crandall most 

 efficiently managed affairs connected with the business office. Capt. 

 James Ross did the collecting offshore, and his interest and willingness 

 are very much appreciated. 



Occidental College, Los Angeles, Calif. 



