THE ZOOPHYTES. 141 



creatures, scarcely perceptible to our unaided sight, but whose 

 operations, though slow, silent, and invisible, are yet certain 

 and increasing : 



Unconscious, not unworthy, instruments, 



By which a hand invisible was rearing 



A new creation in the secret deep. 



Omnipotence wrought in them, with them, by them ; 



Hence, what Omnipotence alone could do, 



Worms did. I saw the living pile ascend, 



The mausoleum of its architects, 



Still dying upwards as their labours closed ; 



Slime the material, but the slime was turned 



To adamant by their petrific touch ; 



Frail were their frames, ephemeral their lives 



Their masonry imperishable. 



MONTGOMERY. 



Amongst the many recent cultivators of this interesting 

 department of natural history, the name of the late Dr. 

 Johnston, of Berwick, stands pre-eminent ; his excellent work 

 on the British Zoophytes has done much to exalt the subject 

 and to diffuse a more general taste for its cultivation. 



"Zoophytes," to adopt the language of Dr. Johnston, "pre- 

 sent to the physiologist the simplest independent structures 

 compatible with the existence of animal life, enabling him to 

 examine some of its phenomena in isolation, and free from the 

 obscurity which greater complexity of anatomy entails. The 

 means of their propagation and increase are the first of a series 

 of facts on which a theory of generation must arise; the 

 existence of vibratile cilia on the surface of the membrane, 

 which has since been shown to be so general and influential 

 among animals, was first discovered in their study, and in them 

 is first detected the traces of a circulation carried on inde- 

 pendently of a heart and vessels. The close adhesion of life 



