sd 
In my opinion this view which of late years has still been defended 
e.g. by Dwicut’), BARDEEN ®), FiscurL ®) is not very satisfying. 
In opposition to this view I wish to hold another, at which one 
arrives when making use of the notions of comparative anatomy 
and certain results of embryology. 
If we cast a look at the above ten formulas, we are struck by 
the difference in the number. of vertebrae as regards both the whole 
vertebral column and the praesacral and the dorsal part. 
In a vertebral column of the formula // 35 vertebrae are extant 
in toto, among which are 25 praesacral and 13 dorsal ones. 
On the contrary we find in a vertebral column of the formula 47/5 
in toto 33 vertebrae, 23 of which are praesacral and 12 dorsal. 
Now comparative anatomy teaches, that if we leave out of consi- 
deration the stages of the vertebral column, which form the beginning 
of the phylogenesis of this organ, a comparatively greater number 
of vertebrae characterizes a more primitive state. Consequently a 
vertebral column of the formula /f is more primitive than a column 
answering to the formula ///d. 
And as embryological investigation *) has shown. us, it is true, that 
a lumbal vertebra can be transformed into a sacral vertebra, but 
the opposite process has not been demonstrated, and further, because 
the study of the development of the vertebral column of man has 
proved, that a little rib can fuse with the transverse process of a 
vertebra, and consequently can contribute to the formation of a 
processus lateralis, but never has anything been observed, which 
1) Tu. Dwieur, Description of the Human Spines showing Numerical Variation 
in the Warren Museum of the Harvard Medical School. Memoirs of the Boston 
Sociely of Natural History vol 5. N. 7. 1901 p. 237—312. 
TH Dwient, Numerical Variation in the Human Spine, with a Statement con- 
cerning Priority. Anatom. Anzeiger. Bd. XXVIII p. 33—40; 96—102. 1906. 
*) Cu. R. BaArpeeN. Numerical vertebral Variation in the human Adult and 
Embryo. Anatom. Anzeiger. Bd. XXV 1904 p. 497—519. 
Cu. R. Barvees, Studies of the development of the human skeleton. With 13 pl. 
American Journ of Anatomy. Vol IV N. 3 p. 265—392 Pl. 1—XIIL. 1905. 
Compare likewise the chapter written by Bsrpeen: “Die Entwicklung des Skeletts 
und des Bindegewebes” in the Handbuch der Entwicklungsgeschichte des Menschen, 
herausgegeben von F. Keren und |. P. Marr. Bd. 1 Leipzig 1910 p. 326, 
p. 360—362. 
3) A. Fiscuer, Untersuchungen über die Wirbelsäule und den Brustkorb des 
Menschen. Anatom. Hefte. Herausgegeben von F. MerkeL und R. Bonner. Bd. 
XXXI p. 459—588. M. Tf. 51—60. 1906. 
4) Regarding the observations to be taken into consideration here, vide; E. ROSENBERG, 
Bemerkungen tiber den Modus des Zustandekommens der Regionen an der Wir- 
belsäule des Menschen Morpholog. Jahrbuch Bd. XXXVI H. 4 p. 609—659, 1907. 
