Fig. 69. Longitudinal horizontal section through the vertebral column of a larva, 5.5 centims. in length, on the level of the hæmal arches, shewing the intervertebral rings of cartilage continuous with the arches, the vertebral constriction of the notochord, &c.
Figs. 70 and 71. Transverse sections through the vertebral column of a larva of 5.5 centims. The red represents bone, and the blue cartilage.
Fig. 70. Through the vertebral region, shewing the neural and hæmal arches, the notochordal sheath, &c.
Fig. 71. Through the intervertebral region, shewing the intervertebral cartilage.
Figs. 72 and 73. Transverse sections through the trunk of a larva of 5.5 centims. to shew the structure of the ribs and hæmal arches.
Fig. 72. Through the anterior part of the trunk.
Fig. 73. Through the posterior part of the trunk.
Plate 42.
Figs. 74-76. Transverse sections through the trunk of the same larva as figs. 72 and 73.
Fig. 74. Through the posterior part of the trunk (rather further back than fig. 73).