142 
OTTO C. GLASER 
SUMMARY 
The nematocysts of eolids are derived from coelenterates, and 
are not to be looked upon as an instance of homoplastic evolution. 
Their defensive value is slight, partly because nudibranchs are 
distasteful to their enemies even in the absence of nettles, and 
partly because many of the ingested nematocysts are adapted to 
meet exigencies in the lives of coelenterates which do not arise in 
those of eolids. A reason other than utility must therefore be 
discovered in order to explain the origin of the nematocyst- 
storing habit. 
BIBLIOGRAPHY 
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