6lO ADDENDA ET CORRIGENDA. 



nified two diameters. B. Filiform compound papillEe ; a. artery; v. vein; c. capillary loops of the 

 secondary papillae [which ought, however, to enter these papillae]; b. line of basement membrane ; 

 d. secondary papillae, deprived of e, e. the epithelium ; /. hair-like processes of epithelium capping 

 the simple papills ; magnified 25 diameters ; g. separate nucleated particles of epithelium, magnified 

 300 diameters. 1,2. Hairs found on the surface of the tongue; 3, 4, 5, ends of hair-like epithelial 

 processes, showing varieties in the imbricated arrangement of the particles; but in all, a coalescence 

 of the particles^towards the point; 5, encloses a soft hair ; magnified 1G0 diameters. 



Page 305, in § 141, insert the following : — According to the 

 most recent observations of Tomes {Microscopical Journal, xv.), it 

 is shown to be extremely probable, that the membrane indicated 

 by Huxley on the enamel of the growing tooth is nothing more 

 than the outermost layer of the developing enamel, detached 

 during the process of examination. Supposing this explanation to 

 be correct, we may regard the enamel as simply an excretion from 

 the cells of the organon adamantine, like the cuticular tissues of 

 many invertebrate animals, which structures, also, are in many 

 cases formed of prisms, as I have elsewhere demonstrated. 



Page 406, line 26, for § 77, read §§ 77 and 85. 



Page 479, at end of second paragraph insert (see figure on 

 p. 482). 



