r f 0 47 which was pink by ninhydrin fraction b 1 3 mg showed this same spot as well as one slightly lower r f 0 44 red by ninhydrin while fraction c 0 2 mg contained both of these and a third one r f 0 34 purple by ninhydrin all three showed good cytotoxicity and pointed cell forming activity with a exhibiting slightly more activity than b and significantly more than c this indicated that the uppermost tlc spot must be from compound s which caused the morphological change in l1210 cells these fractions were not purified further but analyzed as mixtures quantitative bioassay results are discussed below an attempt was made to determine if a particular organ of spisula polynyma contained most or all of the bioactivity a live clam was anesthetized with diethyl ether and then dissected into nine parts foot digestive system gonads siphon gills heart mantle adductor muscles and the remainder of the visceral mass with foot digestive system and gonads removed these were identified by comparison to illustrations of other clams each organ was homogenized in 3 1 methanol toluene and the resulting extract was then triturated with dichloromethane and methanol to remove salts while all of the extracts showed cytotoxicity table only those from the gills and the gonads exhibited strong morphology changing activity that from the digestive system and the remainder of the.