58 THE CELL DOCTRINE. 



table life in the sphagnum leaf, and from animal life 

 in connective tissue and striped muscle. 



As characteristic and distinguishing features of 

 this theory, we desire to point out, first, the substi- 

 tution of the term " endoplast " for " nucleus ; " that 

 of " periplast " for " cell-wall," and " intercellular," 

 " substance." Second, the absolutely passive nature 

 of the " endoplast," which is neither itself the author 

 of changes nor the subject of changes. Third, the 

 passive nature. as well of the "periplast," so far as 

 it is the author of changes, though it is pre-emi- 

 nently the subject of changes, the seat in which changes 

 take place. And herein, we believe Huxley to have 

 been misinterpreted by some who have presented 

 his views elsewhere, as Dr. Beale,* who repre- 

 sents him as believing the periplast active, that it is 

 the efficient agent, that it sends in partitions, etc. 

 But that Prof. Huxley considered it passive we be- 

 lieve may be legitimately inferred from his text. 

 As the seat of change, however, accomplished not as 

 " the result of any metabolic action of the endoplast, 

 but of intimate molecular changes in its substance, 

 which take place under the guidance of the vis essen- 

 tialis" the periplast is differentiated into every variety 

 of tissue. Finally, we have the distinct admission, 

 as seen in the sentence last quoted, and also through- 

 out the entire expression of the theory, of a con- 

 trolling, guiding principle, through which the dift'er- 



* Beale, Microscope in Medicine. Third Edition. London, 

 1867, page 147. Beale, Structure and Growth of the Tissues, 

 London, 1865, pp. 9, 10. 



