OCR Text |
Show 1891.] VARIATION OF T H E L E P O R I N E S T E R N U M . 161 Series of sterna of Lepus cuniculus showing absorption of the seventh sternebra (dorsal aspect). Nat. size. A, B, C, D, E show the seventh sternebra ossified; F, the seventh sternebra only represented in cartilage (the two halves had not as yet completely fused); Gr, normal sternum; H, side view of sternum, showing dorsal displacement of the seventh sternebra ; I, sternum of embryo of 3 cm. total length; J, horizontal longitudinal section of sternum of embryo of 7 cm. total length ; K, longitudinal section of sternum of embryo of 11 cm. total length; L, sternum of embryo of same age. Reference letters : /., fontanelle ; pe., ensiform process ; S. V-VIII, sternebrse. PROC. ZOOL. Soc-1891, No. XI. 11 |