40 THE AQUARIAN NATURALIST. 



tite and its capabilities of digesting food, although 

 how such food is swallowed is a puzzle. 



Innumerable are the forms under which these 

 Foraminifera present themselves, each rivalling the 

 other in delicacy of structure and elegance of shape ; 

 and if we have selected but a single species as an 

 illustration of their structure and habits, we can 

 assure the reader it is by no means on account of 

 deficiency either in the variety or the number of spe- 

 cimens at our disposal. True it is, that not many 

 years ago the very existence of such beings was un- 

 known even to the scientific naturalist; much less 

 did any one suspect that these unseen, these unob- 

 trusive agents were employed in building up the 

 very world on which we tread. Nay, start not, 

 reader; what at first may seem a rash assertion, will 

 bear thorough sifting : to convince yourself, take but 

 a handful of the sand cast up by the retreating tide 

 upon the nearest beach, and, with a pocket lens, 

 examine it minutely, count the various forms you 

 there encounter ; and, if you have sufficient patience, 

 count their numbers too, no easy task sometimes. 



The sand of most sea-coasts is, indeed, so filled with 

 these microscopic Foraminifera, that it is often com- 

 posed of them to the extent of one-half. Plancus 

 counted 6000 in an ounce of sand from the Adriatic 

 Sea, and D'Orbigny, the great historiographer of these 

 minute organisms, reckoned 3,840,000 in an ounce of 

 sand from the Antilles. If we calculate the contents 

 of larger quantities, as, for example, a cubic yard, the 

 amount surpasses all human conception, and we have 

 difficulty in expressing the resulting number in figures ; 



