480 
TRANSFORMA TIONS OF INSECTS. 
Now the pupae of the Cirripedes resemble greatly those of some 
Crustacea which are called Rhizocephala. In both the mouth is 
closed and useless, and the prehensile antennae are developed ; but 
in the Cirripedes there are eyes and some other proofs of a higher or- 
ganisation. The pupae of the Cirripedes attach themselves, as has 
been explained, and those of the Rhizocephala fix themselves to the 
abdomen of common and hermit crabs. The future of the Rhizo- 
cephalous pupae is wonderful, and would be perfectly unique were 
it not for the notice given above of the Anelasma. They remain 
through life without mouth or “any digestive apparatus ; they lose 
all their limbs completely after their metamorphosis from the pupa, 
and appear (writes Fritz Muller) as sausage-like sac-shaped or 
discoidal excrescences upon their victim or “ host,” filled with ova. 
From the point of attachment closed tubes — ramified-like roots — 
sink into the interior of the “ host,” twisting round its intestines 
even, or becoming diffused amongst the sac-like tubes of its liver. 
The only manifestations of life which persist in these non pins 
ultras in the series of retrogressively metamorphosed Crustacea 
are powerful contractions of the roots, and an alternate expansion 
and contraction of the body, in consequence of which water flows 
into the blood cavity, and is again expelled through a wide orifice. 
There is a close resemblance between the early larvse or NaiLplii 
of the Rhizocephala and the Cirripedia , and the likeness of the 
pupae to each other has been noticed ; but then the retrograde 
metamorphosis causes an extreme divergence of character, the 
Anelasma linking, however, the two orders Rhizocephala and 
Cirripedia together, and offering a strong evidence of their former 
common origin. (Fritz Muller, translated by W. S. Dallas.) 
Thus the Crustacea , like some of the other great divisions of 
the Articulata , have some kinds which do not undergo any meta- 
morphosis, and others in which the transformation is very great 
and progressive ; whilst a few forms positively retrograde in their 
development during their wonderful evolution. 
C'ASSliL,L, 
LETTER, AND GALLIN', HKLLE SAUVAGE WORKS, LONDON, E.C. 
