experiments using 25 clams eacla show that the siphons were Ik, J to l6,4 

 percent of the total clam meats, Vhe eijhons were cut from the bodl©« 

 after the manner of commercial ahucking, ia which appioximately j/h of 

 the siphon is remoTed. In two additional experiments usiag 25 clams each, 

 the entire siphons were pulled from the bodies. Separated in this manner, 

 the siphons constituted 18.5 to 19.9 percent of the total clsun meats. In. 

 a semi-commercial operation in which 290 bushels of clams were shucked raw 

 hy a rega].ar shucking crew, who were instructed to cut off all the siphoa 

 carefully, the siphons were 18.5 percent of the total clam meats. The 

 £?paration of the siphons in the present- survey followed the latter method, 



The resu3.ts of the sur&'ey do not show uniformity in the fluctu- 

 ation of toxicities of the clams. Brsn those from plots in the same 

 locality do not always display the sasne vrend. 



There is no eTident correlation between the degree of toxicity 

 and the terrain of the "beach, the magaife^■^.de of the tides, tenrperat'ire of 

 the water, or amount of daylight. However, the data do suggest a recurring 

 fluctuation in the toxicity during the year. 



Goaclugjoas 



A l6 month survey of representative clam beds in Southeastern 

 Alaska verifies the earlier findings that a toxin or toxins, which cause 

 reactions in mice similar to those produced by toxin frequently present in 

 mussels (paralytic shellfish poison), is present In the butter clams of 

 Southeastern ^aska frosa certain areas during every month, 



The toxicity of the siphons is usually several times greater than 

 that of the bodies. 



The toxicity of the bodies does not vary greatly from month to 

 month, while the toxicity of the siphons shows marked fluctuations. 



Literature Cited 



MEDCOr, J. C; LEIM, A. H, ; NEEULEE, AXPEEM B.; HEBULEH, A. W. H,; 

 GIBBAED, J,; and KAUBERT, J. 



1947. Paralytic shellfish poisoning on the Canadian Atlantic coast. 

 Ball. Fish, Ees. Bd. Can., 21. PP. ^H, Ottawa, Ontario, 

 Canada. 



SOMMER, H. , and MBIEER, K, F, 



1937. Paralytic shellfish poisoning. Arch. Path., 24, pp. 560-598, 



Saja Francisco, California. 



SOMMER, HEEMAM; HOMIER, ROBERT P.; BIEGEL, BTBON; STAEGER, D. WAEEBIT; 

 MOLD, JAMBS D. ; WIZHOLM, DOMLD M.; and ZIEALIS, ELIZABETH SHAME SY. 



19^. Paralytic shellfish poison. I. occurrence and concentration 

 by ion exchange, Joor, Amer, Chem, Soc, 22.* PP» 1015-1018. 



