MULTUM E PARVO. 



whales,— the insoluble remains of the Diatoms, 

 originally devoured by the Molluscs, which in their 

 turn found a grave in the stomach of the Cetacean. 

 "We find that the siliceous particles of the Dinto- 

 macese, l'olycistin;i, Acanthometrse, and Sponges, 

 exist not only in a state of the utmost purity, 

 but that they occur precisely in that state of 

 minute subdivision which favours the solvent or 

 aggregative process in an eminent degree. We see 

 that they are gathered together by the Salpae, in 

 the first instance, from the element in which they 

 live, and that they are freed of all, or nearly all, 

 their soft portions, by the action of the digestive 

 cavities of these creatures. We find that the Sal- 

 pae again, in inconceivably vast numbers, afford 

 almost the entire food of the largest orders of 

 Cetaceans; and I therefore think we are able to 

 infer, with certainty, that, in the complex stom- 

 achs and intestines of the latter, the further pro- 

 cess of aggregation of siliceous particles goes on 

 upon a gigantic scale, aided by the presence of the 

 alkalies, and that the aggregated masses being 

 voided at intervals, slowly subside, without inter- 

 ruption, to the bed of the ocean." 



Darwin records having seen clustered objects in 

 the sea near Keeling Atoll, which he does not 

 name, but which from the figures he has given 

 must have been Diatoms. But all the streaks and 

 bands of colour seen on the ocean are not attri- 

 butable to plants : some of them are certainly of 

 an animal nature. The following phenomenon 

 was noticed by the observer last named on the 

 coast of Chili. The vessel passed through broad 

 bands of reddish water, which when examined 

 microscopically swarmed with minute active ani- 

 malcules, darting about, and often exploding. 

 They swam by the aid of a ring of vibratory cilia, 

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