14 THE CELL DOCTRINE. 



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 singularly 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 comic 

 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 magnify ing properties; while lenses 

 themselves have been found in the ruins of Nineveh, 

 Herculaneum, and Pompeii. But it is quite certain, 

 also, that they did not become available as com- 

 pound microscopes until about 1590, when the Jan- 

 sens, father and son, of Holland, are said to have in- 

 vented the compound microscope. Fontana, in 1646, 

 writes that he had invented the microscope in 1618. 

 Galileo, as early as 1612, is said to have sent a micro- 

 scope to King Sigismund of Poland, though whether 

 it w T as his own invention, or made after the pattern 

 of another, is more difficult to determine. In 1685 



