PATELLA. 259 
tacula are white, shortish, rounded, tumid at the bases, taper- 
ing, but not to a fine point, setose, and in young animals 
there is a transparent line from base to point; the eyes are 
small, at the external bases, though raised a little on them. 
The foot, when at rest, is nearly a regular oval, but in action 
becomes greatly elongated, and often puckered anteriorly ; 
the sole is yellowish-white, edged by a fine brown line, and on 
the upper surface has a clouding of bistre hues. No exserted 
organe générateur is seen in this group, therefore the animal 
belongs to that category which is styled “ self-sufficient.” This 
term requires some explanation. 
All the Conchifera, Patelle and Chitons, notwithstanding 
this deficiency, have well-filled ovaria in the genial season ; 
but that is not sufficient without a communion of both the 
sexual influences, which, though they may exist m the same 
body, must be essentially distinct. It will be asked, where, 
and what, are the male organs of this tribe? If the animals 
are examined when the “ genitabilis aura Favoni” impresses 
all nature with its magic influence, they will be found to be full 
of ova, mixed with a milky fluid, which under the microscope 
will appear to proceed from minute membranous bodies inter- 
spersed or attached to the ovarium; these organs may furnish 
the vital powers; but we have searched in vain for them when 
the ova are in a more advanced state. I have also observed 
these phenomena in Dentalium Tarentinum. 
It is only agreeably to the foregoing conditions that I admit 
the doctrine of self-sufficiency. I do not believe that a myste- 
rious, invisible, and unknown principle, contrary to nature as 
handed down to us, and independent of sexual union, exists in 
this, or any other class; the gemme of the Polypi and scis- 
sions of the Monads are not exceptions. I believe that a 
universal law has impressed a distinct sexual union on all 
animated nature. It is m this sense only that animals suffice 
for themselves; that is, they must as fully exercise their 
peculiar, though united, male and female influences, as if 
they were bisexual ; I therefore consider the hermaphroditism 
of this group of that character which I have already desig- 
nated, Venus sine concubiti. 
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