27G PllOF. ALLMAN ON THE RECENT RESEAUCHES 



but his observations were not sufficiently complete to justify him 

 iu maintaining their actual analogy with tbese bodies. 



In connexion with Grreeff's observations on the relations of the 

 nucleus to reproduction luAmoeba terricola, may be here mentioned 

 those of Fr. Eil. Schulze on the behaviour of this body in the 

 multiplication of -4. polypodia. Max Schultze. F. E. Schulze*has 

 seen the nucleus with its nucleolus in this rhizopod divide \>y a 

 transverse constriction ; the two halves recede from one another, 

 and the body of the Amoeba then, by a similar constriction, divides 

 between the two segments of the original nucleus. The process 

 in this case thus differs essentially from that described by Greeff, 

 and corresponds to a well-known form of cell-multiplication. 

 - The Amoeba terricola occurs, according to Grreeff, very frequently 

 in sand and in the earth on the root-fibres of mosses, grasses, and 

 other plants when they do not form too thick a layer on the sur- 

 face of rocks, walls, house-tops, trunks of trees, and the like. It 

 is almost always found in company with terrestrial Arctiscoida 

 (" bear animalcules "), Rotifers, Anguillulae, &c. 



The shallow layer of earth in which it lives frequently ex- 

 poses it to desiccation, when its vital activity is arrested. In 

 this condition the firm hyaline outer layer contracts more and 

 more with the increasing dryness, and thus aftbrds to the soft gra- 

 nular parenchyma a protection against absolute desiccation. 

 When moistened, however,, with water, it once more awakens 

 to complete activity even after a dormancy of many months. 



Among the terrestrial amoebiform organisms discovered by 

 Grreefi' is one which he assigns to a new genus under the 

 name of AmpMzonella. lie distinguishes three species, of which 

 one, A. violacea, has been especially observed by him. The Am- 

 .phizonellee are distinguished from the Amoeboe by being provided 

 with an external soft capsule, which is quite distinct from the 

 proper cortical layer. They have a large round nucleus ; and 

 pseudopodia, which rapidly appear and disappear, are emitted 

 from the interior and bore their way through the external cap- 

 sule, which again, on their withdrawal, becomes so completely 

 closed as to lose all trace of having been perforated. In A. vio- 

 lacea the internal protoplasm is of a beautiful violet colour. Greefi" 

 has witnessed a partial fusion of two individuals. He regards 

 this as a case of conjugation, and believes that it is followed by 

 the formation of a young brood within the body of the parents. 

 * Arch. f. mikr. Anat. vol. xi. p. 592. 



