Table 1. — Percentage of eggs of American oyster and hard clam that developed normally, percentage of larvae that survived, 

 and percentage increase in mean length, in the presence of different concentrations of chemicals ' — Continued 



Compound 



Concentration 



Eggs 

 developing 



Oysters 



Survival of 

 larvae 



Increase in 



length of 



larvae 



Eggs 

 developing 



Survival of 

 larvae 



Increase in 



length of 



larvae 



Insecticides— Continued 



Guthion (1 experiment; water solution) 



Lindane (1 experiment; water solution) 



Malathion (2 experiments; acetone solu- 

 tion) 



N-3452 (I experiment; water solution) 



N-3514 (1 experiment; water solution) 

 Parathion (1 experiment; water solution) 



Sevin (3 experiments; 1 water solution and 

 2 acetone solution) 



TEPP (1 experiment; water solution) 



Toxaphene (2 experiments; acetone solu- 

 tion) 



Herbicides: 



Araitrol (2 experiments; water solution) 



Amitrol-T (1 experiment; water solution) 



2-4-D ester {1 experiment; acetone solution) 



P.p.m. 



.25 



.50 



1.00 



2.50 



5.00 



10.00 



.25 

 .50 

 1.00 

 2.50 

 5.00 

 10.00 



.25 



.50 



1.00 



2.50 



5.00 



10.00 



.50 

 1.0 

 2.5 



5.0 



1.0 

 10.0 



.025 

 .050 

 1.00 



.02 

 .025 

 .050 

 .10 

 .20 

 1.00 

 2.00 

 2.50 

 4.00 

 5,00 

 10.00 



1.00 

 2 50 



5.00 

 10.00 



.25 

 .60 

 1.00 

 2.50 

 5.00 

 10.00 



2.60 

 5.00 

 10.00 

 25.00 

 50.00 

 100.00 

 250.00 

 500.00 

 1.000.00 



.25 



.50 



1.00 



2.50 



5.00 



10.00 



.025 



.05 



.10 



.25 



.50 



1.00 



2.50 



5.00 



10.0 



Ptrcent 

 91 

 65 

 





 



127 

 114 



84 



82 

 43 



104 

 95 



101 

 89 

 SS 

 42 





 

 

 





 



96 

 104 

 106 



90 



100 

 91 



100 

 74 



103 

 95 



104 

 104 

 104 

 94 

 2 



93 

 100 

 48 

 93 

 89 

 88 



90 

 89 

 80 



85 

 27 



Percent 



Percent 



90 

 88 

 66 

 52 

 20 



113 

 117 

 119 

 135 



101 

 93 



101 

 90 



99 

 94 

 100 

 80 

 80 

 96 

 SI 

 5 

 



91 

 89 

 97 

 96 

 104 

 78 



95 

 97 

 80 

 102 

 98 

 



86 

 90 

 77 

 74 

 72 

 41 



103 

 87 

 22 



109 



119 



124 



106 



72 



80 

 70 

 61 

 41 



117 

 111 



96 

 117 

 112 

 116 



71 



Percent 

 106 

 109 

 31 





 



97 

 112 

 111 



116 

 107 

 109 

 105 

 99 

 108 



99 

 95 

 89 

 70 

 100 



106 

 60 



100 



91 

 94 

 77 

 64 

 48 

 

 Ml 



84 

 91 

 51 

 39 

 37 

 



Percent 

 81 

 81 

 38 





 



117 

 102 

 100 



103 



67 



103 



"85" 



33 

 11 





 

 

 



Percent 

 95 

 95 



86 

 98 

 101 



107 

 71 



30 



92 

 '36' 



21 

 5 



See footnotes at end ot table. 



EFFECTS OF PESTICIDES OX DEVELOPMENT OF CLAMS AXD OYSTERS 



399 



