AMON& SIMPLE SAECODE ORGANISMS. 275 



multitude of small vacuoles, we have once more a single large 

 one. 



Small algse, diatoms, and other foreign bodies are also found 

 imbedded in the parenchyma. These have been taken in as nu- 

 triment, and are frequently found enveloped by the yellow bodies 

 already referred to. GrreetF regards these yellow bodies, which 

 are also frequently present in the aquatic AmoebcB, as intended 

 to promote the digestion of the ingested nutriment ; and he com- 

 pares them with the so-called liver-cells, also of a yellowish 

 colour, which clothe the digestive canal in many of the lower 

 animals — an analogy which at best may be regarded as very 

 remote. 



Among the contents of the body occur also minute crystal- 

 line-looking structures, which, however, are without any definite 

 form. GreefF has no doubt that they are a product of the 

 Amoeha itself, and not introduced from without. Similar bodies 

 are known to occur in aquatic Amcebce and other Ehizopoda, 

 where they have been described by Auerbach, Wallich, Carter, 

 and others. 



But the most important structure found in the inner paren- 

 chyma is the nucleus. Like many of the other bodies which are 

 found there, it is carried about by the sarcode currents, and is so 

 soft that it changes its shape when it meets with any obstruction 

 in its course. It is enveloped in a double membrane. It is 

 viewed by Greeff as an organ of reproduction. It consists at first 

 of a homogeneous protoplasm with some dark glistening granules ; 

 but after a time the entire nucleus becomes filled with solid round 

 corpuscles, which he regards as the young progeny of the Amoeba. 

 The outer covering then disappears, and he believes that the 

 solid corpuscles escape into the surrounding parenchyma. The 

 whole of the nucleus thus becomes broken up into the young 

 brood which fills the body of the Amoeha, The Amoeha now 

 ceases to take in food, its motions become less active, and its 

 functions seem to be entirely confined to the protection and 

 development of the young. These are soon ejected, and become 

 developed externally into the form of the parent. Greeff has 

 found such young Amcehce in the surrounding sand. 



In two instances Greefi" observed in the interior of the body elon- 

 gated soft masses apparently composed of bundles of sinuous hair- 

 like filaments, which recalled the supposed spermatic filaments 

 described by Balbiani in the so-called nucleolus of the Infusoria ; 



