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THE CELL DOCTRINE. 



The idea that animals and plants, however com- 

 plex their organization, are really composed of a 

 limited variety of elementary parts, constantly re- 

 curring, was appreciated by Aristotle, who was born 

 384 years before Christ, while it appears to have 

 been little more clearly conceived by the acknowl- 

 edged father of medical science, Galen, who lived 

 400 years later. Aristotle distinguished as " partes ^ 

 similares," those structures, such as bone, cartilage, 

 fat, flesh, blood, lymph, nerve, ligament, tendon, 

 membrane, vessels, nails, hairs, and skin, which 

 were not confined to one part of the body, but 

 distributed throughout it generally. He applied 

 the term "partes dissimilares " to the regions of 

 the head, neck, trunk, and extremities. Fallopius 

 of Modena, 1523-1562, to whom we are indebted for 

 our knowledge of the conceptions of Galen in regard 

 to these " partes similares " or " simplices," has fur- 

 ther developed the subject of general anatomy in his 

 " Lectiones de Partibus Similaribus Humani Corpo- 

 ris." These, however, plainly do not correspond 

 with the " elementary parts " or " cells " of the pres- 

 ent day. As Prof. Huxley says in his valuable essay 



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