Fig. 9 From a specimen (551, 5-2-16) of the early flexure stage; fixation, Van 

 Gehuchten's fluid; staining, erythrosin and toluidin blue; sections, 7 n, longitudi- 

 nal and in an obliquely vertical plane. 



Fig. 10 From a specimen (564, 3-2-19) of the early 'coil-reaction' stage; fixa- 

 tion, Zenker's solution; staining, iron hematoxylin; sections. In, in the frontal 

 plane. 



Fig. 11 From the same specimen (564, 3-2-17) as the last. 



Figs. 12 to 13 From the same specimen (564, 3-2-18) as the last. 



Figs. 14 to 15 From a specimen (555) of the typical 'coil-reaction' stage; fix- 

 ation, Van Gehuchten's fluid, staining, erythrosin and toluidin blue; sections, 

 7 p., longitudinal and in an obliquely vertical plane. 



Fig. 16 From a specimen (505, 1-2-15) of the 'S-reaction' stage; fixation, 

 sublimate-acetic; staining, alum carmine in toto and Lyon's blue in 95 per cent 

 alcohol acidulated slightly with hydrochloric acid; sections, 10 ju, in the frontal 

 plane. 



Fig. 17 From a specimen {bO?),' 1-2-11) of the 'S-reaction' stage, treated as 

 the last but in the sagittal plane. 



140 



