108 Dr Grant's Observatio?is on the 



those which had descended into the bodies of the polypi, and 

 those found loose in the jar, were of the full size and deep-red 

 colour. None of the imperfectly formed white ova were detach- 

 ed from the sides of the canals, or seen in the polypi. I 

 collected carefully the loose ova from the bottom of the jar, 

 and on placing them in a watch-glass with sea-water I could 

 perceive with the naked eye that they continually changed their 

 situations, gliding to and fro with an almost imperceptible mo- 

 tion. Viewed with the aid of a lens, their motions were ob- 

 vious ; they were seen to contract themselves frequently during 

 their progressive motions, and sometimes they appeared revolv- 

 ing round their axis. When placed under the microscope, and 

 viewed by transmitted light, they appeared as opaque spheres 

 surrounded with a thin transparent margin, which increased 

 in thickness when the ova began to grow, and such of the ova 

 as lay in contact united and grew as one ovum. A rapid cur- 

 rent in the water immediately around each ovum, drawing 

 along with it all loose particles and floating animalcules, was 

 distinctly seen flowing with an equal velocity as in other cilia- 

 ted ova, and a zone of very minute vibrating ciliae was per- 

 ceptible, surrounding the transparent margin of all the ova. 

 The progressive motion of the ova, always in a direction con- 

 trary to that of the current created by their ciliae, was very 

 obvious, though less rapid than in any other zoophyte in 

 which I have observed the same remarkable phenomenon. 

 The specimen suspended in the 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 mo- 

 tions and progress of the groups of ova passing through the 

 colourless bodies of the polypi. 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 polypi, 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 tlie beautiful contrast of colours, the 



