NUMERICAL VARIATION IN THE HU.-MAN SPINE. 'l\t 



G-19. Cat. 9379-5. 



Female, white. C. 7, T. 12, L. 5, (S. 5, C. 5 ?) . 



The 12th pair of ribs are very small. The left one has a minute, but distinct head 

 in a socket, while the right one is even more rudimentary, being incorporated with other 

 parts so as to suggest a transverse process. The left one measures 2 cm. ; the right one is 

 3 mm. shorter. Seen from the front, the right one continues the line of the heads of the 

 ribs; seen from behind, it is distinctly a transverse process. The 19th vertebra as a whole is 

 thoracic rather than lumbar, the spinous process being thoracic and the change of the arti- 

 cular processes occurring below it. The spread of the lumbar transverse processes is not 

 characteristic, as it is about equal in the lower four, but those of the 4th lumbar have the 

 penultimate outline. There seem to be 9 or 10 sacral and coccygeal vertebrae. The 5th 

 sacral looks very much like a coccygeal fused with the sacrum. Little if any of the 3d 

 sacral touches the ilia, but it has the conjugata vera. Below what I have called the 

 sacrum there are 4 or 5 coccygeals fused together. The 11th pair of ribs measures, on 

 each side, 15 cm. along the concavity. This increase of length is common when the last 

 pair is rudimentary or with lumbar characteristics. Although the spine was not measured 

 fresh, it is evident to the eye that proportion requires that the 19th vertebra be considered 



thoracic. 



In this spine the tendency in the 19th to assmne a lumbar character has gone further 

 than in the preceding, one sign of which is the chsturbance of the customary rule of de- 

 velopment of the lumbar transverse processes. 



(In the two preceding cases there is a tendency for the 19th vertebra to assume 

 lumbar characteristics ; in the two following it is for the 20th to assume thoracic ones.) 



636. Cat. 9379-36. 



Male, white, aet. 28. C. 7, T. 12 or 13, L. 5 or 4, S.and C. 10. 



The costal elements of the 1st lumbar are separate. The left one seems like a trans- 

 verse process that has not fused with the body, but the right one has both the shape and 

 size of a rib. There is a distinct head in a socket. The length of the right one is 4.3 

 cm., aijd of the left 2.5 cm. The lumbar transverse processes are very pecuhar, those of 

 the 21st and 22d being uncommonly strong, and those of the last two unconunonly small. 

 The last is very ill developed, suggesting that of a penultimate. On the right they in- 

 crease in length to that of the 23d, on the left to that of the 22d. That is to say, if we 

 consider the 20tb a hunbar vertebra on the left and a thoracic on the right, the 3d lumbar 

 on each side has the greatest spread. The change of the articular processes is normal, 



