SYSTEMATIC ZOOLOGY BY C. J. MAYNARD. 103 



their jelly-like protoplasmic structures with which they secure feed in a 

 manner quite similar to that explained under the head of amoeba on a fol- 

 lowing page. Propagation is by fission. 



PROVINCE KHIZOPODA. 



Root-footed Animals. 



Many forms of this group are also naked drops of jelly- 

 like protoplasm, but differ from the monera in having a nu- 

 cleus and a contracting vesicle. Some members of the 

 province are, however, covered with a calcareous shell by 

 which they are protected. 



ORDER FORAMINIFERA. 



Animal either naked or provided with a shelly cover- 

 ing of carbonate of lime. 



Foraminifera. These animals are covered with a cal- 

 careous shell, which is pierced with holes, and from these 

 are thrust out and withdrawn jelly-like arms, known as 

 pseudopodia. With these, food is captured, and the ani- 

 mal also moves by their aid. 



The foraminifera are inhabitants of the water, and are found in all oceans, 

 excepting, possibly the Polar seas. Small as they are, many being micro- 

 scopic in size, although others, as will be seen, exceed a quarter of an inch 

 in diameter, these animals play a very important part in the economy of nature. 

 They do the first work of collecting the organic matter contained in sea water, 

 converting it into living substances. ( It is noteworthy that this organic 

 matter is returned to the sea water as fast as it is withdrawn by vegetable 

 life in the form of the sea weeds). The foraminifera also imbibe lime from 

 sea water, of which they form their shells. They are then in turn eaten by 

 animals higher in the scale of life. These animals are often provided with 

 lime shells as in the mollusks, sea urchins etc., or with a stony base as in 

 corals, and these calcareous deposits are finally, to a great extent, converted 

 into lime stones, which form the greater portion of islands in tropical seas. 



Then when we look back into the past history of the world, and exam- 

 ine the calcareous deposits of the Secondary and Tertiary Epochs, we find 

 that the chalk beds are almost wholly formed of the remains of foraminifera 

 themselves, as are also the so-called Nummulitic limestones of which the Egypt- 

 ian pyramids are made. There is also a strong reason for believingthat the older 



