140 
OTTO C. GLASER 
SO seriously crushed during the trials that cost them their cerata, 
that the behavior of the fish could be due to nematocysts in 
other parts of the animal, so that obviously unpalatability to 
certain fish is a common property of nudibranchs, and by no 
means limited to the nettle-bearing species or individuals. 
If these results, which are in complete harmony with those of 
Cuenot, are surprising, this is largely due to a common misappre- 
hension as to the nature and significance of nematocysts. When- 
ever the word nematocyst is employed, it not unnaturally calls to 
mind the stinging artillery of a Discomedusa, or of a Portuguese 
man-of-war. Such armament is quite misleading, for its tremen- 
dous effects are by no means typical. Indeed the forms from which 
nudibranchs derive their nematocysts are themselves subject to 
attacks from the same fish which under certain circumstances will 
devour an eolid, and if the nettles of Eudendrium and of Tubu- 
laria do not protect them against browsing blennies, pinfish, and 
minnows, it is not to be expected that the game nettles transferred 
to another animal will gain in effectiveness. 
In addition, the observations of Toppe ('09) suggest an impor- 
tant clew. Apparently the structural specialization among nemato- 
cysts is accompanied by specialization of function; for while some 
kinds serve as nettles, others are prehensile organs, and have noth- 
ing whatever to do with the infliction of wounds. These facts 
are very significant, for, aside from correcting a misconception 
widely spread, as to nematocysts in general, we now know defi- 
nitely how the various kinds function and how beautifully each is 
adapted to certain specific ends. The adaptiveness of these 
structures is not in themselves, but comes about as the result of 
the habits of the animals producing them. It would be surprising 
indeed if a nematocyst, adapted to curl round the chitinous hairs 
of a copepod should be protective when exploding in the mouth of 
Fundulus. 
Toppe's results suggest further that defense is not the original 
function of nematocysts, but that they are prim.aril}^ organs of 
prehension for the purpose of entangling prey. From this stand- 
point it appears that the nettling function proper is secondary. 
