Arctic Natural History. 77 



brownish slimy substance was observed floating in loose floc- 

 culi amongst it, in the surface of the water. The naked eye 

 could detect in it no structure whatever ; but on viewing a 

 drop of it through a microscope which magnified about two 

 hundred and fifty diameters, it was found teeming with ani- 

 mal life, and minute vegetable forms of very great beauty. 

 Now would have been the time to perpetuate them with the 

 pencil and chalk, but unfortunately I could only consign them 

 to the bottle, with the expectation that their delicate silicious 

 shells would retain their forms until our arrival in England. 

 No one can conceive the vast numbers of these infusorial ani- 

 malcules in the polar seas. Varying in size from z £o to xoV o 

 of an inch, a single cubic inch will contain perhaps four or 

 five hundred millions of individuals, each furnished with per- 

 fect instruments of progression. In some of them I could see 

 the cilia in rapid motion, while, to use the words of Professor 

 Jones, '* they were swimming about with great activity, avoid- 

 ing each other as they passed in their rapid dance, and evi- 

 dently directing their motions with wonderful precision and 

 accuracy."* In others no cilia could be detected ; but as they 

 too were seen in motion, although not so often as the others, 

 there is no doubt that they also possess similar delicately 

 constituted organs. A beautiful sieve-like diatoma was very 

 abundant ; but the shells which are silicious were broken very 

 readily. They resemble the Coscinodiscus minor of Kutzing. 

 Colour of the Sea. — I do not think that these infusoria can 

 be included in the forms of animal life, described by Captain 

 Scoresby, under the comprehensive genus Medusa, which is 

 very abundant in the Greenland seas visited by that most dis- 

 tinguished arctic voyager ; nor does there appear to be the 

 slightest resemblance between them, except that both are of 

 very minute size. He says that the sea is sometimes of an 

 olive-green or grass-green colour. This is not at all peculiar 

 to the still bays in Davis Strait, where the infusoria are so 

 abundant. This phenomenon applies to the sea generally for 

 many leagues or even degrees, and is not confined to the sur- 

 face only ; neither is it essential to that condition that there be 



* A General Outline of the Animal Kingdom, by T. R. Jones, F.Z.S., 1841. 



