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Observations on the Polyzoa. 

 By a. H. H. Lattey, M.R.C.P.* 



(Bead October 27th, 1871.) 



Amongst the vast number of animated beings, of whose very- 

 existence we should have remained in profound ignorance, were it 

 not for the invention of the microscope — so justly termed a sixth 

 sense — few afford more beautiful or interesting objects for our con- 

 templation than the group to which the name of Polyzoa has been 

 given ; so called from two Greek words — polus (many) and zoon 

 (animal) — being always found aggregated together in masses, and 

 many of them resembling minute plants, so much so as to have l)een 

 classed, by early observers, amongst the members of the vegetable 

 kingdom. Their complex organization has obtained for them a 

 high position in the animal kingdom, and the exquisite form which 

 some of them possess cannot fail to excite our admiration. When, 

 for instance, we see the elegant Sertularians, projecting like fairy 

 ferns from the side of a rock-pool, attractive by their graceful 

 forms, even before the microscope has revealed the beautiful little 

 creatures studding their branches like living flowers, or the Poly- 

 zoary of the Halodactylus, with its exquisite bell-shaped creatures 

 emerging, one by one, from the jelly-like mass coating the seaweed, 

 like the ribs of a folded umbrella, stripped of its covering, and then 

 gradually expanding into a beautiful bell, the cilia? fringing its 

 ribs, or tentacles, in perpetual motion, keeping up a constant eddy 

 in the surrounding water, so as to bring the floating particles of 

 nutritious matter within the grasp of their open mouths. 



* Communicated by Mr. T. Curteis, F.R.M.S. 

 JouRN. Q. M. C. No. 18. B 



