50 



PHYSIOLOGICAL SEKIES. 



particular being so taut and powerful that the vertebral 

 column, even before the removal of the trunk-muscles, is 

 bent into serpentine curves. Towards the tail both liga- 

 ments are reduced in size. 



B. 18. Two transverse sections of the vertebral column of a Shad 

 (Clupea alosa), taken from the trunk (upper specimen) and 

 tail regions respectively, to show the relations of the sub- 

 vertebral ligament to the aorta. 



B. 19. Anterior portion of the vertebral column, and posterior 

 part of the cranium of a Cod (Gadns morrhua), showing 

 the powerful subspinous ligament. It is partly attached to 

 the arches, as shown in the lower part of the preparation by 

 the removal of the left halves of two of the arches. 



B. 20. Four vertebrae of a Cod (Gadus morrliua] 

 end view of the ligament. 



INTERARCUAL. 



giving an 



B. 21. Seven dorsal neural arches and spines of a Sheep (Ovis 

 aries) showing the yellow elastic tissue (Ligamenta subflava) 

 by which the arches are united. Its probable duty is to 

 reestablish the normal curves of the spine after muscular 

 action. 



AT VERTEBRAL JOINT OF RIBS. 



B. 22. Six vertebrae of a Snake (Python sebce), with portions of 

 the ribs left attached to the lower three. In front of the joint 



Fig. 4. 



X20. 



the attachment of the rib to the vertebra is effected by a 

 plate of yellow elastic tissue, the elastic fibres are closely 

 packed, parallel to one another, at its fixed ends cartilage 



