i QO THE PSYCHIC LIFE 



It is superfluous to insist upon the importance of 

 these results, obtained by a method that might be 

 called experimental physiology applied to unicellular 

 organisms. Although the experiments have been 

 made solely with ciliated Infusoria, the results of the 

 same may be extended to all cellules, for the Infusoria 

 are nothing more than autonomous cellules living an 

 independent life. 



The conclusion from the above researches of M. 

 Balbiani, which, as we have seen,- go far beyond those 

 of Gruber, is, that the nucleus is not necessary merely 

 to the regeneration of the parts, as the German pro- 

 fessor believed. The error made by Gruber arose 

 from the fact that he did not follow the career of the 

 fragments deprived of a nucleus long enough; if he 

 had continued his observations, he would have seen 

 that the fragment becomes gradually disorganized. 

 The nucleus, accordingly, has not merely a formative 

 power; it does not merely regulate alimentation, re- 

 adjustment of form, and the healing of wounds; it has 

 not merely a regenerative power, enabling the plasma 

 to reconstruct complete the organs lost by artificial 

 severance. The nucleus is, besides all this, an essen- 

 tial factor of the plasm's "vitality. If a fragment ot 

 protoplasm be deprived of i^s nucleus, the fragment 

 remains alive for some time, but afterwards under- 

 goes disorganization. 



Such are the facts, extremely complex, and conse- 

 quently difficult to summarize by a formulated state- 

 ment. 



under the same conditions (that is, in a drop of water on a glass slide kept in 

 the moist chamber of Malassez): in this way it is possible to keep them alive 

 for the space of a month, by introducing into the liquid a few Infusoria to serve 

 them as food. On the other hand, the fragments deprived of nucleus by sec- 

 tion live for only eight days at the most. 



