58 Barnacles of the Species hepas anatifera. 



minute pedicles branching from the greater stems; which are 

 not all transparent, but, through more than half their length, 

 are of a very dark indigo or blackish-purple colour. 



The great singularity of those under consideration is, that 

 the shells serve as the ground of attachment for fresh pedicles ; 

 so that the specimens form a chain, of which the links are 

 alternately pedicles and shells, as may be seen in jig. 2. b : 

 and so numerous are these links, that there are, in some cases, 

 a series of four, and even five, alternations ; not occupying 

 altogether, in many of the smaller ones, a space of more than 

 2 in. Nor are these alternations limited to the larger spe- 

 cimens, but even the most minute exhibit them ; as if age was 

 not required for their production. How the ova, of which 

 Dr. Weatherill speaks (V. 341.), are detached and impreg- 

 nated (if what he observed be ova), appears difficult to explain. 

 The " numerous very small round bodies, attached to one another 

 by cellular tissue," I have observed ; but they appear to me to 

 be glandular, and portions of the creature itself. It is a 

 structure, I think, not dissimilar to certain peculiar parts of 

 the human frame. In the specimens before me, the pedicle is 

 evidently hollow, at least where it is inserted into the shell ; 

 and, towards that part, I observed the water in motion, and the 

 small particles afloat therein attracted, as if drawn thither by the 

 suction of the animal ; which process was noticed by several 

 persons. Dr. Weatherill speaks of joints in the tentacula. I 

 dissected one of the largest of my specimens, and find that 

 there are two strong joints (Jig. 2. n a), distinct from those 

 which, I imagine, he speaks of, which reminded me of what I 

 have seen in insects having strongly contractile springs. The 

 tentacula, also, act in pairs, each pair being inserted into a 

 lobe ; several of which lobes make up the body of the JLepas : 

 the length of the tentacula being inversely to the size of the 

 lobes and the nearness of them to the stem (c). On opening 

 the shells, the animal looks, at first, something like a shrimp ; 

 but that arises from its curved, feathery, round appearance. 

 On squeezing the lobes, two substances are immediately 

 separated : the one of a perfectly milky white, and the other 

 of a true burnt-sienna colour : the latter more consistent than 

 the former, and both opaque ; the former lining the cavities 

 of the hollow tentacula as well as the lobes, from which it is 

 extricated in curd-like particles. It is possible that a very 

 high microscopic power would detect in these substances not 

 merely a thick fluid, but some structure which would show 

 them to be (if not excrement or aliment) endowed with func- 

 tions necessary to the life and health of the animal. The 

 tenacity with which it retains life has been exemplified by the 



