PAPERS OX BIOLOGY AND AGRICULTURE 219 



BIBLIOGRAPHY. 



Gotte, A., 1S97. L'eber den Wirbelbau bie den Reptilien und einige 



anderen Wirbelthieren. Zeits. wiss. Zool., 62, 1S97. 

 Hay, O. P., 1S97. Structure and mode of development of the vertebral 



column. Science, IV. 1S97. 

 Howes, G. B.. & Swinnerton. H. H., 1901. On the development of the 



skeleton of the tuatara, Spenodon punctatus. Trans. Zool. Soc. 



London. 1901. 

 Schauinsland. H.. 1906. Die Entwickelung der "Wirbelsaule der Wir- 



beltiere nebst Rippen und Brustbein. Handb. d. Entwicklung- 



slehre. 3 pt. 2. 1906. 



EXPLANATION OF PLATE. 



Fig. 1. Cross section of a notochord of an alligator embryo, 6 mm. 



long. 



Fig. 2. Diagrammatic sketch of the myotomes in the trunk region, of 



a 6 mm. embryo, showing the origin of the scleroblastic cells. 



Fig. 3. Side view of the notochord and the spinal cord of a young 



alligator, showing the position and arrangement of the 



vertebral components. 



Fig. 4. A single pair of sclerotomes, which show their position and 



their relation to the notochord and the spinal cord. 

 Fig. 5. A ventral view of the notochord, showing the series of hypo- 



chordal bars in the trunk region. 

 Fig. 6. Neural arch and haemal arch formation, and their connection 

 with the hypochordal bar. 



neural arch 

 notochordal sheath 

 sclerotome 

 scleroblastic cells 

 segmental blood vessel 

 spinal cord 

 spinal ganglion 

 vacuole 

 ventral nerve root 



