226 
J. BEARD. 
Fig. 56. — Section, trank region, T. ocellata. Z. D, oc. 2. 
Fig. 57. — Section, spinal cord region, Scyllium canicula. The epiblast 
is not represented. Z. I), oc. 2. 
Fig. 58. — Section through developing anterior root of a spinal nerve, 
Mustelus. Z. F, oc. 2. 
Fig. 59.— Section through tail region, T. ocellata. H. 8, oc. 2. 
Fig. 60. — Section of developing anterior root (near anus), Mustelus. 
Z. D, oc. 2. 
Fig. 61. — Section through trunk region, T. ocellata. Z. D, oc. 2. 
Fig. 62. — Section, head region, Chick with no somites. Z. D, oc. 2. 
Fig. 63. — Section in region of infundibulum, Chick, nine somites. Z. D, oc. 2. 
Fig. 64. — Copy of Kleiuenberg’s figure of developing parapodial ganglion 
(yj. g.) of Lopadorynchus. The sketch has been turned through 180 degrees. 
Figs. 65 and 66. — Section, head region, Chick embryo with nine somites. 
Fig. 67. — Section, head region, Chick embryo with four somites. Z. D, oc. 2. 
Figs. 68 and 69. — Two sections through trunk and head regions respectively 
of a Chick embryo with four somites. Z. D, oc. 2. 
PLATE XX. 
All the figures on this Plate are from Chick embryos. All are under Zeiss’s 
D, oc. 2. 
Figs. 70 — 76. — Series of sections through trunk region, from behind for- 
wards, of an embryo with six somites. 
Figs. 77 — 79. — Series of sections from before backwards through brain 
region of an embryo with nine somites. 
Fig. 80. — From same embryo, but through first somite. 
Fig. 81. — From same embryo, but through end of second somite. 
Figs. 82 — 84. — Three sections through brain region of an embryo with 
seven somites. 
Fig. 85. — Section through spinal region of same embryo. 
Figs. 86 and 87. — Two sections through brain region of two embryos with 
no somites. 
Fig. 88. — Section, hind-brain region of a Chick embryo with ten somites. 
Fig. 89. — Section, trunk region of a Chick with eight somites. 
PLATE XXI. 
Figs. 90 and 91. — Two longitudinal frontal sections through the head of a 
three-days’ Chick embryo, showing the rudiments of branchial sense organs. 
Z. A, oc. 2. 
m = Mesocephalic ganglion and sense organ. 
v. Trigeminus „ „ 
wt. Facial ,, ,, 
ix. Glossopharyngeal „ „ 
