Present State of Nematocyst 



Research: Types, Structure 



and Function 



Cadet Hand 



Department of Zoology, University of California, Berkeley, CalifomiOi. 



I want to start by quoting an admirable passage from the Intro- 

 duction of the recent paper by Burnett and colleagues (1). On 

 page 247 they state "One of the most structurally complex and cer- 

 tainly one of the most enigmatic organelles in the animal kingdom 

 is the nematocyst of coelenterates. For nearly a century hosts of 

 scientists, too numerous to mention, have concentrated their at- 

 tentions on the mode of formation, the migration pathways, the 

 mechanism of discharge, and the chemical nature of these unusual 

 structures. . . ." These same authors go on to make the statement 

 that ". . . none of these subjects of investigation has been resolved to 

 any degree of satisfaction." In many ways this statement is accu- 

 rate and acceptable, but I think in many ways I would disagree with 

 the generality. A good deal is known about each of the subjects 

 they cite and I for one have found considerable satisfaction in the 

 numerous papers on nematocysts that I have examined. I also want 

 to acknowledge that some of my satisfaction has come from reading 

 the papers of Burnett and his co-workers. 



I want to talk today about types, structure and function of nema- 

 tocysts. I also want to make it clear that I do not work on nemato- 

 cysts, I work with them. My interests in them are twofold. First, 

 nematocysts are a truly \'aluable systematic tool and many coelen- 

 terates can be positively identified by their nematocysts alone. Not 

 only this, but nematocysts are useful in relating higher taxa such 



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