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praesacral vertebrae, that of Leveling (1787). Unfortunately, in most 

 cases the vertebral formula is not given ; still in many it is reported 

 normal, and in a few reduced. To this case should perhaps be added 

 the two cases of Leboucq, in which there was an additional cervical 

 vertebra with a cervical rib on the 8th, and the case reported by 

 Lane, already mentioned. Above all there is Rosenberg's spine with 

 25 praesacrals and 15 ribs, the first being a cervical one. This spine, 

 indeed, is a most satisfactory one from Rosenberg's point of view; 

 but, admitting its authenticity, it stands alone ; the overwhelming mass 

 of observation is just the other way. Thus there are two spines, 

 Leveling's and Rosenberg's, with cervical ribs and an increase of 

 praesacral vertebrae not in the cervical region. On the other hand 

 there are several instances of reduction of the number of praesacrals, 

 and this occurs with the most perfect specimens of cervical ribs; so 

 that while the upper part of the spine is archaic, the number of 

 praesacrals is diminished, which is thought to be a progressive feature. 



Turning now to rudimentary 1st ribs: in G-22, which is not a 

 perfect case, as the 1 st ribs are only small and not rudimentary, there 

 is an extra thoracic vertebra; in A-4, a typical case, there is the 

 same ; in an incomplete specimen there is a record of 6 lumbar vertebae ; 

 Leboucq describes a case with one praesacral too few, and another 

 with one too mauy^). Here we are confronted by the fact that while 

 the upper part of the spine shows an alleged step towards the future, 

 the lower part shows one towards the past. Surely such a series of 

 diametrical contradictions, both in the cases of cervical ribs and of 

 imperfect 1st thoracic ones, is fatal to a theory, to say nothing of 

 the difficulty of accounting for the fusion of the atlas and occiput on 

 evolutionary grounds, and ignoring the question whether cervical ribs, 

 if archaic, are not too archaic to be taken seriously. 



It cannot be denied that it is a very serious criticism on Rosen- 

 berg's theory that a tendency at either end of the spine either to 

 revert to the past or to stretch forward to the future may be asso- 

 ciated with a tendency at the other of a directly opposite significance. 

 The question then arises whether there is not some explanation that 



1) The last case of rudimentarj^ 1st rib seen at this writing, 

 ist that of Low (Journ. of Anat. and Physiol., Vol. 34). There are 

 25 praesacral vertebrae, of which 13 are thoracic. The last rib on the 

 side of the rudimentary 1st one is very much larger than its fellow. 

 The last three lumbar vertebrae seem normal, except for some sacra- 

 lization on one side of the last. It is on the same side as the rudi- 

 mentary rib. There is an extra vertebra in the thorax. 



