14 THE CELL DOCTRINE. 



on "The Cell Theory," they were ultimate to Fallo- 

 pius, because he could go no further, " though it is, 

 of course, a very cliflferent matter whether we are 

 stopped by the imperfection of our instruments of 

 analysis, as these older observers were, or by having 

 really arrived at parts no longer analyzable."* These 

 " partes similares " really correspond to the " tissues " 

 of the present day, which are collections of elementary 

 parts. The conceptions of these older writers with 

 regard to the " vital endowment " or " independent 

 vitality " of their similar parts or tissues, were sin- 

 gularly correct, and correspond almost identically 

 with those held by the majority of physiologists of 

 the present day. 



Further than this, however, the anatomists of the 

 period of Fallopius could not go — not because, as we 

 now well know, they had arrived at parts no longer 

 analyzable, but because of their imperfect means of 

 analysis. 



It is probable that the magnifying properties of 

 lenses were known to the Egyptians, as well as the 

 Greeks and Romans, over 2000 years ago ; since 

 a table of refractive powers is introduced into 

 his "Optics" by Ptolemy, since Aristophanes, the 

 Athenian poet (B.C. 500), speaks of "burning 

 spheres" of glass as sold in the grocers' shops of 

 Athens, and since both Pliny and Seneca refer to 

 lenses and their magnifying properties ; while lenses 

 themselves have been found in the ruins of Nineveh, 



* The Cell Theory— a Keview, by T. H. Huxley ; Br. and For- 

 eign Med. Chir. Kev. for October 1853, No. xxiv. 



