Beitr. z. Morphologie u. Entwicklungsgeschichte d. Vogelbeckens. 749 
Spur von Trennung zeigt. Dadurch erweist sie sich eben nur 
als ein einfacher Fortsatz des Iliums, dem meiner Ansicht nach 
keinerlei phylogenetische Bedeutung züzusprechen ist.“ 
„Auf Sagittalabschnitten des jüngsten Stadiums ist diese 
Spina iliaca als eine nicht unbeträchtliche Erhöhung bemerkbar» 
welche aber allmählich kleiner wird, so daß sie auf den ältesten 
Stadien schließlich nur als eine ganz flache Erhebung sichtbar 
bleibt und an dem Ilium des erwachsenen Tieres gänzlich ver- 
schwunden ist. Das Pubis, dessen basaler Teil, wie schon oben 
erwähnt ist, den ventralen Rand des Acetabulums bildet, hat auf 
dem jüngsten Stadium schon seine definitive, dem Ischium und 
Ilium parallele oder nahezu parallele kaudale Richtung einge- 
nommen.“ 
BRoom, R. (1906). „In the 10-day ostrich embryo the 
pelvis is well developed and much of it is chondrified. The ilium 
is of large size and is developed both much in front of the ace- 
tabulum and far behind it. The preacetabular portion is a deep, 
flat plate, which extends forwards in the direction of the lumbar 
vertebrae. Posteriorly the ilium narrows very considerably and 
curves downwards and backwards along the curved caudal vertebrae. 
The acetabulum is relatively of large size and is imperforate, being 
completely closed by the ilium, pubis, and ischium. The pectineal 
process is of large size, but it appears to be formed by the pubis 
rather than the ilium. If this be so, then the head of the pubis 
is unusually broad. The lower part passes downwards and curves 
slightly backwards, and is a slender, cartilaginous rod. At its 
lower end it passes into a broad sheet of procartilage which 
connects it with the ischium. Near the lower end of the carti- 
laginous portion a slight condensation of connective tissue or 
procartilage cells probably represents the early stage of the pre- 
pubis. The ischium has a very broad head which joins with the 
ilium and the pubis, and forms much of the acetabulum. From 
this it passes downwards as a broad bar of cartilage, then curves 
forwards as it passes into the sheet of procartilage, which unites 
it with the lower end of the pubis. There is no symphysis of 
the pubes or ischia, each being a considerable distance away 
from its neighbour of the opposite side. 
In the 11-day embryo the condition of parts is much more 
like that of the adult. The pectineal process, though still large, 
is relatively much smaller. The pubis and ischium are longer 
and relatively more slender and they pass more backwards. The 
