26 VIEWS OF THE MICROSCOPIC WORLD. 



COLORED TRACTS OF THE OCEAN. It has been noticed by navigators in all 

 parts of the sea, that extensive tracts of water are not unfrequently discolored at a 

 great distance from land. This change in the hue of the waves is caused by the 

 presence of minute marine animals and Infusoria, which impart their own tint to 

 the waters in which they abound, the far greater part being too small to be ob- 

 served by the naked eye. Nearly one-fourth of the Greenland sea, comprising an 

 area of more than twenty thousand square miles, is of a deep olive green hue. 

 This coloring matter was discovered . by Mr. Scoresby to consist of animalcules, 

 which crowded the water in infinite numbers. On an average, sixty-four animal- 

 cules of one kind were found in every cubic inch of water submitted to examina- 

 tion, and, on the supposition that they were equally numerous throughout the 

 body of colored water, Mr. Scoresby computed, that a surface of two square miles 

 and fifteen hundred feet deep, contained no less than twenty-three thousand 

 millions of millions of animalcules belonging to one species. And in order to 

 form a more definite idea of this vast multitude, he remarks, that the number 

 of years required for eighty thousand persons to count them, would be equal to 

 the period that has now elapsed since the creation of the world. 



This green sea is described as the Polar pasture ground, the animalcules 

 affording an exhaustless supply of sustenance to creatures less minute, and these 

 likewise becoming the food of larger species, which in their turn are devoured by 

 others of greater size. And thus the series continues to increase until the waters 

 are crowded with numerous forms and types of animal life, the prey of the mighty 

 monsters of the deep, which in vast numbers resort to these prolific seas. 



On the east coast of Greenland Mr. Scoresby also met with broad patches and 

 bands of water of a yellowish-green color, as if sulphur had been strewn upon 

 the waves ; and upon examining it with a microscope it was found swarming 

 with animalcules. Most of them were of a globular form and of a lemon color, 

 and seemed to be possessed of little activity, but the rest were in constant mo- 

 tion. So small were these creatures that the largest did not exceed the two- 

 thousandth of an inch in length, and many of them were but half this size. A 

 single drop of the water, and that not the most discolored, was found to contain 

 more than twenty-six thousand animalcules. The glass upon which the drop 

 was placed for examination was ruled into small squares of equal size. The drop, 

 when magnified linearly one hundred and sixty-eight times, covered five hundred 

 and twenty-nine of these squares ; and in every square, on an average, fifty ani- 

 malcules were found ; which made an aggregate of twenty-six thousand four 

 hundred and fifty. Mr. Scoresby computed, that in a tumbler of water one hun- 

 dred and ffty millions of these animalcules would find ample room, and regard- 

 ing each as one-four-thousandth of an inch long, a row of half a million placed 

 closely side by side, would form a line only ten feet and five inches in extent. 

 Oft' the coast of Chili, at the distance of fifty miles from shore, Darwin passed 

 in the ship Beagle through wide bands of turbid water; a single tract in one 

 case comprising an area of several square miles. When viewed at a distance, 

 the waves appeared red, but under the shade of the vessel, of a deep chocolate 



