10 



SYDNEY EVANS JOHNSON 



solute alcohol to which has been added 1 per cent of strong 

 ammonia. At the end of four hours the ammonia fixative is 

 poured off and leplaced with fresh fluid. In this the tissue 

 should remain from two to four days. The tissue is then rinsed 

 in distilled water and put into a 7 per cent solution of nitric 

 acid for twelve hours.^ 



ABBREVIATIONS 



Ac.O., accessory organ 



And., auditory vesicle 



And.Gn., auditory ganglion 



Br.O., branchial sense organs of Beard 



B.Cl., basal cell 



Buc.VIL, Ramus buccalis VII 



Can., canal wall 



Clm., columnar supporting cell 



Der., dermis 



Dt.En., ductus endol>nnphaticus or its 



pore 

 Dor.L., dorsal line of pit organs or 



their anlagen 

 Dor.O., dorsal line organ 

 Ect., ectoderm 



Ep.Po., epidermal pocket or tunnel 

 Epd., epidermis 

 Ep.Fl., epidermal fold 

 Fbr., terminal fibrillae 

 Fb.Zn., longitudinal filler zone 

 Grp., one group of 'hair-cells' 

 H., hair-like process of secondary 



sense cell 

 Hym., hyomandibular canal 

 I. Orb., infraorbital canal 

 I.Orb.Cd., infraorbital sensory cord 

 Lat.NiK, nervus lateralis 

 Lat.Cn., lateral canal or its pores 

 Lat. Gn., lateral ganglion 

 Medl., spinal medulla 

 Mn.Ex.VII, ramus mandibularis ex- 



ternus VII 



Mnd., mandibular canal 



Mnd.Pt.O., mandibular line of pit 

 organs 



M.N J., medullated nerve fiber 



Mus., muscle 



N.M.Fb., non-meduUated nerve fil)ers 



Po., pore of tubule 



Pt.O., isolated pit organs or their an- 

 lagen 



R.Dor., ramus dorsalis of lateral nerve 



P. Supt.y ramus supratemporalis of 

 lateral nerve 



Rml., ramulus lateralis 



Rt., root of lateral nerve 



Sn.CL, secondary sense cell 



Sn.Col., sensory column 



S.Orb., supraorbital canal 



S.Orb.Cd., supraorbital sensory cord 



Spn., spindle-shaped supporting cell 



Sp.Gn., spinal ganglion 



Sup.O}>h.VII, ramus ophthalmicus 

 superficialis VII 



Supt., supratemporal commissure 



Tu6., tubule 



Var., varicosity 



Vas., vascular space or blood cell 



v., fifth nerve, root, or ganglion 



VII, seventh nerve, root, or ganglia 



IX, glossopharj'ngeal, root, or gan- 

 glion 



.v., vagus, roots, or ganglia 



'After the manuscript for this paper had gone to The Wistar Institute, my 

 attention was drawn to the fact that a practically identical modification of 

 the pyridine silver method was employed in 1913 by G. C. Huber and S. R. 

 Guild, and is described in the authors' paper on the peripheral distribution of 

 the nervous terminalis in mammalia. The Anatomical Record, volume 7, page 

 253. 



