122 ESCHRICHT AND REINHARDT 



The variations just mentioned in the dimensions of the lumbar vertebrae are not quite 

 uniform in accordance with their natural order of succession. This is especially true in speaking 

 of the transverse processes, the direction of which, is somev?liat irregular, as we have already 

 stated. Thus it happens that, while the breadth of the vertebrae still perceptibly increases in the 

 anterior part of the lumbar region, yet this increase may be stopped, nay, perhaps a slight 

 decrease may be found in some of the vertebrae, and what might seem even more remarkable, in 

 the same lumbar vertebra the left transverse process may be even one inch longer than the right 

 one, or vice versa. 



While these changes are taking place in the dimensions of the lumbar vertebrae, and more 

 especially while the vertebral bodies are continually increasing in circumference, whereas 

 the processes are indeed at first also increasing in size, but then again, on the contrary, very 

 much decreasing, the appearance of the vertebrae must of course be very considerably altered. 

 But the form of these vertebrae is moreover influenced in another and most important way by 

 the altered position of the articular processes in the most posterior part of this region. In the 

 anterior two thirds of the lumbar region these processes are almost similar to those of the 

 very hindmost part of the dorsal region. In the foremost two lumbar vertebrae they still 

 diverge five inches and a quarter and five inches from each other, and at the same time they 

 are almost quite perpendicular. They still retain this perpendicular position in the succeeding 

 six vertebrae, while they also approach somewhat nearer to each other. But from the tenth 

 lumbar vertebra they are bent so towards the sides that their inner surface becomes concave 

 and inclined in a somewhat upward direction, and the distance between them at their upper 

 extremities becomes five inches and three quarters in the eleventh vertebra, seven inches in the 

 twelfth, and nine inches and a half in the thirteenth one. At the same time they retain about 

 the same size, so that in the most posterior lumbar vertebrae they are fully as large as the 

 very much diminished transverse processes, and form at the same time an angle of about thirty 

 degrees with the spinous processes, and one of sixty degrees with the transverse processes, instead 

 of being perpendicular; these five processes in each of the vertebrae here appear like rays regularly 

 shooting out from its uppermost half, only that the spinous process points backwards, and the 

 transverse processes somewhat forwards. 



During the increasing growth of the vertebral bodies in the lumbar region from before 

 backwards, their form (as we have already hinted) also becomes essentially altered. In the 

 preceding bodies we can only distinguish an upper or spinal siu-face, and a semicircular convex 

 ventral surface, between which the limits are to be found at either side, very high up, at 

 the root of the arch and transverse processes ; but from the fourth lumbar vertebrae the arch, 

 already considerably reduced, has advanced upwards on the superior siu"face ; whereas the semi- 

 circularly convex ventral surface is divided, on either side, into a superior and an inferior part 

 by the two transverse processes, placed much lower in these vertebrae, and the two inferior parts 

 are finally separated from each other by means of a very prominent keel in the mesial line. 

 The anterior, as well as the posterior margin of the body, at the same time, projects so much 

 inferiorly, that two lateral depressions are formed, which seem to have an upward conti- 

 nuation in the broad and shallow grooves behind the transverse processes. But such is not the 

 case in the most posterior lumbar vertebra ; for in this these two lateral excavations are united 

 into one transverse groove, which is continued upwards, both before and behind the short 

 transverse process. The transverse groove is limited inferiorly, both in front and behind, at 



