254 



University of California Puhlications in Zoology [Vol. 38 



Table 5 



Eeproduetion of table 4 by excluding all except night hauls 

 (6 P.M. to 6 AM.) 



This table shows that an average of 58 solitary forms per hour was 

 obtained in the colder water and an average of 125 per hour in the 

 warmer water, while an average of 220 aggregate forms per hour was 

 obtained in the colder water and an average of 118 in the warmer 

 water. Table 5 also shows that the frequencj^ of both generations was 

 81 in the colder water, while that of solitary forms was 63 and that 

 of aggregate forms 79 in the warmer water. Thus, table 5 corroborates 

 table 4 in every respect, solitary forms again appearing in greatest 

 abundance and least frequency in the warmer water, while aggregate 

 forms appear in greatest abundance and greatest frequency in the 

 colder water. 



Even when the data are arranged in every other practicable M^ay 

 with respect to light, as in table 6, the same relations persist. 



Table 6 



Relation of surface distribution of Salpn democraticn to temperature 

 with respect to different periods of the day 



Solitary forms Aggregate forms 



Specimens Frequency 



Specimens Frequency 



Tempera- 

 ture in 

 centigrade 





= - o 2 :; 





15?9-18?3 

 18?4-20?8 



15?9-18?3 

 18?4-20?8 



15?9-18?3 

 18?4-20?8 



15?9-18?3 

 18?4-20?8 



A — Including ouh' daylight hauls (6 a.m. to 6 p.m.) 

 21 12.6 10.7 922 73 85 95 10.7 8,944 710 

 13 8.7 5.9 2,162 249 68 82 4.7 1,216 140 



B — Including only intense light hauls (10 a.m to 2 P.M.) 



8 4.1 4.1 226 55 100 100 4.1 3,811 930 



5 3.9 3.4 789 202 87 93 3.1 1,067 247 



C — Including onlj^ early morning hauls (6 a.m. to 10 a.m.) 



9 5.8 4.2 534' 92 72 86 4.2 2,617 451 

 4 1.95 0.9 365 187 46 71 0.9 76 39 



D — Including only evening hauls (6 p.m. to 10 p.m.) 



6 4.4 4.4 324 74 100 100 4.4 1,621 368 

 18 11.5 6.2 2,374 206 54 70 6.2 911 79 



