and Preserving Animals. 283 



In order to preserve the specimens expanded, they should be remo- 

 ved and placed alive in a dish of sea- water ; and when they have 

 protruded and expanded their tentacles, the solution should be 

 slowly and quietly added to the sea- water, when the animal may be 

 killed and fixed in its expanded state. So prepared, the specimens 

 should be transferred to a bottle oi' fresh solution. 



In like manner the minute polypes of the flexible or horny corals 

 may be preserved, protruded from their cells, and expanded. If a 

 small piece of corrosive sublimate is put into the vessel of sea-water 

 containing such living polypes, it will kill or paralyse them when 

 protruded, as it slowly dissolves ; but they must be removed as soon 

 as they have lost their power of retraction, otherwise their tissue is 

 rendered fragile, or is decomposed. The polypes, or animal part 

 of the calcareous kinds, called " Madrepores," " Millcpores," 

 "Fungse," "Red Coral," " Gorgonise," &c., require for their pre- 

 sei'vation, in connection with their supporting basis, the following so- 

 lution (No. 2.) : — 



Solution, No. 2. 



Bay Salt, . . . . J lb. 



Arsenious acid, or white oxide of arsenic, 20 grains. 



Corrosive sublimate, . . 2 grains. 



Boiling rain-water, ... 1 quart. 



All the polypes concerned in the formation of coral reefs, atolls, 

 or coral islands, may be preserved in the above solution, provided 

 they be killed by its gradual application as above described, and be 

 afterwards transferred into fresh solution. With regard to the struc- 

 ture and formation, and mode of observation of coral islands and 

 reefs, the work by Chailes Darwin, Esq., on the Structure and Dis- 

 tribution of Coral Reefs (8vo, 1842), should be consulted.* Never 

 fail to ascertain, if possible, to what depth below the surface of the 

 sea the corals descend, and on what basis they rest ; and for particu- 

 lar instructions with reference to coral reefs, see Mr Darwin's re 

 marks under the head of " Geology." 



Infusorial Animalcules (Polygastria, Polythalmia, Phytolitharia.^ 



Some idea of the value and importance of attending to the collec- 

 tion of these microscopical organized beings may be had by reference 

 to Ehrenberg's observations, forming Appendix, No, V. of Captain 

 Sir James C. Boss's Antarctic Voyage, vol. i., p. 339; a better 

 idea by the perusal of Ehrenberg's numerous communications to 

 scientific journals, some of which have been translated in Taylor's 



* See also, on this subject. Lieutenant Nelson's paper " On the Geology of 

 the IJeniiudas ;" Geological Transactions, Second Series, vol. v., pp. 103-123. 



