144 LECTURE vin. 



LECTURE VIII. 



BRYOZOA.* 



If a deeper and truer insight into the structure and vital properties 

 of the low-organised, ramified, composite, hydriform polypes, which, 

 like little trees adorned with polypetalous flowers and supporting 

 their annual crop of deciduous fruit or seed-capsules, deceived such 

 clear-sighted observes as Tournefort and Ray as to their real nature, 

 and were classed by them with vegetables ; if organised beings, so 

 obviously like plants in external form and in some of their most con- 

 spicuous changes, can be proved by the anatomist to belong unequi- 

 vocally to the Animal Kingdom, without the determination being 

 vitiated or obscured by any real or essential vegetable character ; — 

 if the calcareous masses of Madrepores and Millepores, classed by 

 Boccone and Gruison as species of minerals, and which once were the 

 subjects of curious speculations on the growth of stones, have been 

 proved by the recognition of the more complicated organisation of 

 the polypes which they support, to be the products of the vital actions 

 of such polypes, and as essentially a part of those animals as the 

 skeleton of a man is a part of his body ; — still more does the ana- 

 tomical structure of the third division of polypes prove how in- 

 adequate is a superficial survey of an organised being to lead to true 

 notions of its nature and affinities. The Bryozoa, which coat, as 

 with a delicate moss, fuci, shells, or other marine productions, or 

 which rise in dendritic forms, like the hydrozoic corallines, with 

 which they were associated by Ellisf, with which they would equally 

 Imve passed for plants with Ray, are, perhaps, the most striking 

 examples of how complicated an animal structure may be masked by 

 mere outward form. 



A locomotive organised being must possess an internal digestive 

 store-room ; but the converse of the proposition does not hold good, 

 — a digestive cavity does not imply the powers of locomotion. 



The Bryozoon has not merely a digestive cavity, like the Hydra 

 and the Actinia ; it has not merely the characteristic mouth and 

 radiated prehensile organs for the capture of living prey ; but it has 



* Ehrcnberg, CXXXIII. (1827), Pohjzoa. Thompson, CXXIII. p. 92. (1830.) 

 Ciliobrachiata, Farrc, XXXV 



t This accurate obsen'cr, however, places many of the Bnjozoa in a family, as 

 " cellifcrous corallines," distinct from the " vcsiciUatcd " and " tubular " corallines, 

 XCVIL p. 33. 



