108 VITALISM AND SCHOLASTICISM 



pressure as in the experiments above detailed, 

 the lines of division are vertical in all cases, so 

 that the segmented egg finally forms a plate, 

 a flat plate, of eight cells. Now if these cells, 

 thus formed into a plate, are released from the 

 pressure under which they have been develop- 

 ing they at once again divide in an approxi- 

 mately horizontal plane, so that sixteen cells 

 now make up the congeries. The subsequent 

 course of the development of these shows that 

 some of the cells with, of course, their included 

 * nuclei, which would under normal circum- 

 stances have been worked up into one part of 

 the body, are, under the altered conditions, 

 actually converted into another. The signifi- 

 cance of this experiment will be obvious to any 

 one who considers it, but that significance will 

 be increased when it is remembered that the 

 results negative certain views which were held 

 as to the specific character of the nuclei. It 

 was held by some that the nucleus of each cell 

 was of a specific character and could produce 

 a cell of one type and of one type only. Even 

 if this were the case it would not have helped 

 us very far towards an explanation of the 

 powers of the cell, for we should still be 

 ignorant of how the nucleus succeeded in so 

 modifying the cell as to make it lead to the 

 development of a liver or of some part of the 



