BAENACLES ; THEIK FACTS AND THEIK FICTIONS. 
397 
the luckless host. This ’would be beneficial to the future 
parasite, as securing a better hold; and variations in this 
direction 'would consequently be preserved as advantageous. 
As soon as the ducts had penetrated, an osmotic interchange of 
fluids 'would take place, the balance of benefit being against the 
“ host ; ” and since this source of nourishment 'would be more 
constant than the some’what precarious livelihood casually 
gotten by the waving cirri, the latter organs, together with their 
neighbours, the trojphi^ finding their “ occupation gone,” would 
in time atrophy, while the quondam cement-ducts would 
become nutriferous rhizomes. Those Cirripedes having a 
constant means of subsistence would be better off than their 
less fortunate relations who still kept on “ living from hand to 
mouth,” and would outstrip them in the “struggle for ex- 
istence.” Protected by the abdomen of its Porcellanus host, 
or by the lodging “ annexed ” by the hermit Pagurus, it would 
gradually leave off its calcareous coat and become at last 
“ only a soft sack filled with eggs, without limbs, without 
mouth or alimentary canal, and nourished, like a plant, by 
means of roots, which it pushed into the body of its host. 
The Cirripede had become a Khizocephalon.” * The Anelasma 
squalicola, which lives upon sharks in northern seas, repre- 
sents the halfway stage of this transformation. Here the 
shell-less test is supported on a peduncle which is beset with 
hollow filaments which “ penetrate the shark’s flesh like 
roots.” On the other hand, the cement-glands, are absent, 
the parts about the mouth minute, and the cirri destitute of 
bristles. 
Having begun the article, now concluded, with myths, we 
bring it to a close with “ matters of fact ; ” but we think that 
it 'will be conceded, that sometimes “ hard facts ” and even 
scientific speculations, are no less strange than fiction and the 
wildest flights of fancy. 
LIST OF PRINCIPAL WORKS REFERRED TO. 
JBurmeister^ Hermann. ^‘Beitrage zur Naturgeschichte der Ranken- 
fiissler” (Cirripedia). 4to. Berlin, 1834. 
Cams, Victor. leones Zootomicse.” Tab. x. figs. 33-44. Leipzig, 1857. 
Clarh. “ A List of Dissections in the University Museum, Cambridge.” 
* It is significant that the Cirripedia and RJiizocephala, when in the Nau~ 
plius stage, have more points in common than they have with the Nauplii of 
other Crustaceans. 
