METABOLIC CHANGES 331 



Non-nucleated portions of Funaria hygrometrica behave some- 

 what differently, in that they are able to dissolve starch, but 

 cannot develop it, even if they remain alive for six weeks. 



When a Vaucheria thread is divided into various sized masses 

 of protoplasm, seme of which contain nuclei, we find that the 

 vital activity of these, as well as the separation of a new cellulose 

 membrane, depends upon the presence in each, of at least one 

 cell-nucleus. (Haberlandt, VIII. 4.) 



Results, which are no less important than those obtained with 

 plants, are observed when Amoebce, Reticularia and Ciliata are cut 

 up. Nussbaum (VIII. 9), Gruber (VIII. 3), Hofer (VIII. 6), and 

 Verworn (VIII. 10) all agree that only nucleated parts are able to 

 replace organs which they had lost, and thus to reconstruct them- 

 selves into normal individuals, that grow and multiply. Non- 

 nucleated portions, even when they are larger than the nucleated 

 ones, are unable either to replace the lost organs or to grow, but 

 for some time, often for more than fourteen days, appear to lead a 

 kind of pseudo-existence; eventually, however, they disintegrate. 

 Thus the formative activity of protoplasm appears to be primarily 

 influenced by the nucleus. This is less certainly established in 

 the case of the other functions of the cell, viz. power of move- 

 ment, irritability and processes of digestion. As regards these the 

 opinions of different observers vary. 



Hofer observed that a non-nucleated portion of an Amoeba, 

 after the first stage of irritability occasioned by the operation had 

 passed off, exhibited for from fifteen to twenty minutes, move- 

 ments which were nearly normal. He ascribes this to an after- 

 effect of the nucleus, which, he considers, exerts a regulating 

 influence upon the movements of the protoplasm. For whilst, 

 further, the nucleated part extends pseudopodia like a normal 

 individual, and propels itself forwards, the non-nucleated part 

 contracts up into a round body, and only occasionally, after pauses 

 of many hours' duration, makes abnormal, jerky movements ; it 

 does not attach itself to the bottom of the glass, as crawling 

 Amoebce do, and in consequence vibrates upon the slightest move- 

 ment of the water. 



Verworn discovered that the protoplasm in Difflugia was still 

 more independent of the nucleus. Even small non-nucleated por- 

 tions extended long finger-like pseudopodia in a manner character- 

 istic of an uninjured Rhizopod, and continued their movements 

 even for five hours. Further, they were unimpaired as regards 



