330 G. E. COGHILL 



Figs. 55 to 60 Early swimming stage (No. 496, sections 1-5-4 to 9). X 500. 

 Six successive serial transverse sections through the entrance of the roots of the 

 seventh and eighth nerves into the brain. Figure 55 is the most rostral of the 

 set. In this figure the ascending divisions of the lateral line component {L.L. 

 VII,Asc.a,b) and the roots of the visceral sensory component iR.Vn,Vis.) and 

 the auditory root R.VIII) are beginning to enter. The lateral line roots (R.L. 

 L.VII,a,b) enter in figures 56 to 59. In figure 58, 59 and 60 the fibers of the vis- 

 ceral sensory component have become the fasciculus solitarius {Fas. Sol.), and 

 the descending auditory root fibers (yiII,Des.) appear along the dorsal margin 

 of the descending trigeminal tract (Tr.Des.V). Neurones of the second order 

 (Neu. II) here lie across the entire sensory zone. These figures should be com- 

 pared with figure 6. 



