MORPHOLOGY AND BIOLOGY. 19 



stained specimens and represent the nuclei of the 

 daughter amoeba? which are forming within the parent 

 organism. In Entamceba lustolytica these bodies are 

 often numerous and represent the collections of idio- 

 chromidia which form the nuclei of the young para- 

 sites which are produced by gemmation. 



Besides the vacuoles and the spore-like bodies just 

 noted, there may occur, in the endoplasm of amoebae, 

 minute crystals of various kinds which have been 

 taken up from the surrounding media, as well as 

 bacteria and foreign particles of varying nature. In 

 the parasitic amoebae found in man the endoplasm 

 often contains red blood cells if intestinal inflamma- 

 tion be present. 



GENERAL BIOLOGY. 



Amoebae obtain nutriment by means of pseudo- 

 podia which are protruded from the body and sur- 

 round food materials which are then taken into the 

 body of the organism where they undergo digestion. 

 In these organisms we meet with the most primitive 

 form of digestion, any portion of the cytoplasm being 

 capable of absorbing and digesting food materials. 

 In those amoebae which possess a contractile vacuole 

 the food material is enclosed within it and digested, the 

 residue being expelled when the vacuole contracts. In 

 those organisms in which a contractile vacuole is absent 



