Plants alive in unchanged Sea-water. 265 



curious and often brilliant-hued animals, such as the rarer shelled 

 Mollusca, the graceful Nudibranchs, and the numerous species 

 of Sea-anemones, that are so seldom seen by any one bufcthe 

 professed naturahst. ''J^ ^bot.Y/-ijj« iwDi^ vi't \'> 



But more prominent still was the anticipation ' that by this 

 plan great facilities would be afforded for the study of marine 

 animals under circumstances not widely diverse from those of 

 nature. If the curious forms that stand on the threshold, so to 

 speak, of animal life, can be kept in a healthy state, under our 

 eye, in vessels where they can be watched from day to day with- 

 out being disturbed, and that for a sufficiently prolonged period 

 to allow of the development of the various conditions of their 

 existence, it seemed to me that much insight into the functions 

 and habits of these creatures, into their embryology, metamor- 

 phoses and other peculiarities, might be gained, which otherwise 

 w^ould either remain in obscurity or be revealed only by the 

 wayward '^ fortune of the hour/^ 



Nor were these expectations wholly unrealized. My experi- 

 ments, though not yet entirely successful, and needing much 

 more attention and time to complete them, have yet established 

 the fact, that the balance can be maintained between the plant 

 and the animal for a considerable period at least, without dis- 

 turbance of the water ; while my vivaria have afforded me the 

 means of many interesting researches, the details of which I am 

 preparing for the press. :^'^ i \;i'iimr yiij Iv 



The first thing to be done was to obtain the Algse^ift'ia gtbw- 

 ing state. As they have no proper roots, but are in general 

 very closely attached to the solid rock, from which they cannot 

 be torn without injury by laceration, T have always used a ham- 

 mer and chisel to cut away a small portion of the rock itself, 

 having ready a jar of sea-water into which I dropped the frag- 

 ment with its living burden, exposing it as little as possible to 

 the air. The red sea-weeds I have found most successful : the 

 Fuci and Laminaria, besides being unwieldy and unattractive, 

 discharge so copious a quantity of mucus as to thicken and 

 vitiate the water. The Ulvce and Enteromorphce on the other 

 hand are apt to lose their colour, take the appearance of wet 

 silver-paper, or colourless membrane, and presently decay and 

 slough from their attachments. The species that I have found 

 most capable of being preserved in a living state are Chondrus 

 crispus, the Delesserice, and Iridea edulis. The last-named is the 

 very best of all, and next to it is Delesseria sanguinea, for main- 

 taining the purity of the water, while the colours and forms of 

 these render them very beautiful objects in a vase of clear w^ater, 

 particularly when the light (as from a window) is transmitted 

 through their expanded fronds. Many of my friends, both sci- 



