the Animal and Vegetable Organisms in Sea Water. 321 



were cemented in places against the slate at the back and ends, 

 and at parts along the water-line, so that the creatures could 

 hide themselves at pleasure ; a short beach of pebbles was also 

 constructed in order that shallow water could be resorted to if 

 desired. The whole tank was covered with a light glass shade to 

 keep out the dust and retard evaporation. 



With the sea water obtained in January 185.2, I have been 

 working without cessation up to the present time, agitating and 

 aerating when it became foul during the unsuccessful experi- 

 ments on the sea-weeds, but since then it has been rarely ever 

 disturbed ; the loss which takes place from evaporation being 

 made up, as before stated, with rain or distilled water. 



For a considerable period, after commencing these experi- 

 ments, I was much troubled to obtain living subjects in a healthy 

 condition, but having alluded to this, and the success of my in- 

 vestigations, in a short notice appended to a paper published in 

 the 'Annals of Natural History' for October 1852, my friend 

 Mr. P. H. Gosse, who was then sojourning at Ilfracombe for his 

 health, offered in the kindest manner possible to supply me with 

 materials, and from that period he has always most heartily re- 

 sponded to my wants. It must not be imagined for a moment 

 that the beautiful creatures I have thus received have been all 

 preserved alive or always quite healthy. In experimental investi- 

 gations this would be unreasonable to expect, as the very fact of 

 experimenting implies a disturbance of the then state of things. 

 Besides which, from want of a sufficient knowledge of natural 

 liistory, from want of forethought and experience and other 

 causes, I have lost many veiy tine specimens ; and as the detail of 

 these losses may prevent the occurrence of the like anno3'ances 

 to others, I shall venture to occupy your time for a short period 

 with their history. 



My greatest loss arose from too great an anxiety to transfer 

 the collection I had preserved in a healthy condition to the end 

 of December 1852 into the new tank. As soon as it an*ived 

 from the maker's I lost no time in introducing my numerous 

 family to their new abode, and dearly I paid for my precipitancy, 

 for on the next morning I found many of my most beautiful spe- 

 cimens dead ; thus I lost two fine Holothurias [H. Pentactes), a 

 small freckled Goby [Gobius minutus), a beautiful little Pipe- tish 

 {Syngnathus lumbriciformis) , and several others, and on opening 

 the door of the case the cause of this mortality was at once evi- 

 dent, — an iridescent film of oily matter was floating on the sur- 

 face of the water, arising from the paint with which the angular 

 joints and edges of the small tank had been coloured not having 

 become sufficiently hardened. 



Another source of loss arises from the several creatures attack- 



