18 ALICE JOHNSON. 



logous with the Pubis, while he calls the bone generally 

 known as the pubis the epi-pubis. But since the acetabular 

 regions of each bone always remain cartilaginous longer than 

 the other parts, and since this cartilage is replaced in the 

 adult by a bony process of the Ischium shutting out the pubis 

 (Epi-pubis of Hoffman) from the acetabulum, I should be 

 more inclined to agree with the older view that Hoffmann's 

 pubis is merely a part of the ischium. This seems to me quite 

 consistent with his own account of the ossification. He says: 

 — (loc. cit. p. 186) " Die Verknocherung dieses vorderen Ace- 

 tabularfortsatzes des Sitzbeines fangt zuerst an der dem Sitz- 

 bein angrenzenden Partie an und schreitet so allmahlig dem 

 vorderen Fortsatz des Iliums zu,'erreicht diesen aber erst bei 

 ganz ausgewachsenen alten Thieren." The fact that tlie 

 pubis is moveable in the crocodile is quite sufficient to account 

 for its being shut out from the acetabulum. 



So far as I know, the only literature bearing directly on the 

 subject of the development of the pelvic girdle in birds is a 

 paper by Bunge.' According to him, the pubis and ischium 

 are at first situated with their long axes in a position vertical 

 to the vertebral column, and later become rotated backwards, 

 thus taking on the adult form. This statement has been 

 generally accepted, but T am unable to agree with Bunge's 

 other conclusions. He has omitted to mention the primary 

 continuity of the femur and girdle and the existence in the 

 embryo of an anterior branch of the pubis which becomes the 

 pectineal process. Speaking of the pectineal process in the 

 adult, he only says that his account of the development proves 

 that it is a part of the ilium, and he therefore retains the name 

 " Spina iliaca " given it by the older anatomists. He also 

 concludes that the avian pubis is homologous with the pubis 

 of Reptiles. He describes the pubis as originating indepen* 

 dently of the other elements of the girdle and beginning to 

 fuse with them about on the eighth day. I find that the 

 pubis is absolutely continuous with the girdle at the earliest^ 



' A. Bunge, " Untersuchungen zur Entwickelungsgeschiclite des Becken- 

 giirtels der Ampliibien, Eeptilien, und Vogel," Dorpat, 1880. 



