216 THE MICROSCOPE. 



with each other, serve to maintain a communication between the indi- 

 vidual polyps constituting the mass. The rest of the polypidom is 

 made up of a transparent gelatinous substance, containing the calcare- 

 ous spicula above mentioned, and pervaded by numerous small fibres, 

 which form a sort of irregular network. Alcyonidse are always 

 attached to submarine bodies. The species already mentioned is ex- 

 ceedingly common round our coasts so much so that, as Dr. John- 

 ston says, " scarce a shell or stone can be dredged from the deep that 

 does not serve as a support to one or more specimens." 



" The ova," says Professor Grant, " when placed under the micro- 

 scope, and viewed by transmitted light, appeared as opaque spheres 

 surrounded with a thin transparent margin, which increased in thick- 

 ness when the ova began to grow, and such of the ova as lay in contact 

 united and grew as one ovum. A rapid current in the water imme- 

 diately around each ovum, drawing along with each all the loose 

 particles and floating animalcules, was distinctly seen moving with 

 an equal velocity as in other ciliated ova ; and a zone of very minute 

 vibrating cilia was perceptible, surrounding the transparent margin of 

 all the ova. The progressive motion of the ova, always in a direction 

 contrary to that of the current created by their cilia, was very obvious, 

 though less rapid than in any other zoophyte in which I have observed 

 the same remarkable phenomenon. The specimen, suspended in a glass 

 jar filled with pure sea-water, I now brought so close to the transparent 

 side of the vessel, that I could examine through it, with the assistance 

 of a powerful lens, and without disturbing the animal, the motions and 

 progress of the groups of ova passing through the colourless bodies of 

 the polyps. To the naked eye, at first sight, all appeared motionless. 

 The deep vermilion hue of the small round ova, and the colourless 

 transparency of the outer covering of the polyps, formed a beautiful 

 contrast with the pure white colour of the delicate longitudinal folds, 

 the central open canal, and the slender filaments which wind down 

 from its sides towards the clusters of white ova at the base : but the 

 living phenomena discovered within were even more admirable than 

 the beautiful contrast of colours, the elegant forms, and the exquisite 

 structure of all the parts ; when observed with a lens, the ova were 

 seen to be in constant motion, and quite free within the bodies of the 

 polyps. They moved themselves backwards and forwards, and fre- 

 quently contracted their sides, as if irritated or capable of feeling. I 

 could observe none passing upwards between the stomach and the sides 

 of the polyps. They never assumed the appearance of a string of beads 

 enclosed in a narrow, short, curved tube, as represented by Spix, but 



