PLATE 5 
Figs. 22 to 25 from a 10.9 mm. embryo, are camera tracings to show the character 
of the placodal spur of the VII projecting laterally and caudally. Components 
are indicated as in preceding plate and in fig. 1. Lateralis or special cutaneous 
cross hatched; general visceral vertical lines; placodal or special visceral, stipple; 
figs 23, 24 and 25 are from consecutive sections. Two sections lie between figs. 22 
and 23. The portion of this ganglionic complex shown in stipple is that which can 
be positively identified as placodal in origin. That more of the geniculate or 
general visceral should be shown as derived from the placode is possible, if the 
placodal cells have metamorphosed into ganglion cells. See fig. 28 for detail of 
fig. 23. 
Fig. 26 shows the histological detail of the general visceral and placodal gan- 
glia in fig. 19. The color differentiation due to size and density of cells is well 
shown in this figure. Length of embryo 10 mm. 
Fig. 27 shows the detail of dorso-lateral, ventro-lateral and geniculate ganglia 
posterior to the placodal portion in a 10 mm. embryo. This section lies two 
sections posterior to that shown in fig. 21. 
Fig. 28 shows the detail of the geniculate ganglion and the ventro-lateral 
ganglion in a 10.9 mm. embryo. This figure gives the histological detail of fig. 
23 minus the dorso-lateral VII. Fig. 28 should be compared with fig. 26, since they 
are taken through approximately the same region of the geniculate ganglion of 
embryos differing nearly 1 mm. in length. The constancy in appearance of the 
placodal ganglion is striking. 
