Spawning, completed 1105 



, delaying 1133 



, during 100 



events 415 



in laboratory 1388 



in winter 1131, 1132 



, induced 238, 281, 445, 904, 1128, 1226 



, intermittent 99 



marks on shells 711 



, mass 102 



patterns differ from winter patterns 1433 



period 154, 621, 964, 990, 1255, 1303, 1335, 1360, 2120 



potentiality 89, 99, 102, 104 



season 278, 1602 



___ mid-April to early May 9 55 



stock 68, 823 



temperature 281, 962, 1520, 1527, 1528, 1571, 1602 



lower farther north 1571 



range 987 



time 6 67 



unit 296 



year, good 102 



years 1246 



Species 12, 40, 183, 203, 489, 491, 1278, 1281 



, American 152 



, commercially important 2094 



composition, control of 526 



density 2061 



, description of 1466 



__, disappearance of many animal 2031 



distribution 125 



_________ few 426 



, indigenous 874 



, mass production of important 1251 



, most 202 



, presence or absence of particular 552 



, recent 424, 425 



, southern 1751 



-specific effect 703 

 , substitution of 694 



, type 425, 905 



Specific gravity 418 

 Specificity 125 

 Specimen, aberrant 1723 



, live 1324 



, malformed 359 



Specimens, living 456, 771, 824, 953 



813 



