ANATOMY OB CACOPUS STSTOMA. 



539 



especially birds where the ilia are not merely attached to but 

 cover the sacral vertebrse." In this Indian toad, however, the 

 cartilaginous appendage in question not only covers the epiphysis 

 of a sacral transverse process, but is also attached to an ilium. 

 From the outer surface of the same appendage arises the ilio- 

 lumharis, a muscle which in Rana starts from the distal end of 

 the ilium. These facts probably indicate that it really belongs 

 to the latter, in which case the remarks quoted above may be, 

 with less diffidence, applied also to the same ilio-sacral relation 

 in Cacopus. 



The pubis is interesting, as it exhibits signs of ossification 



A. 



Text-figure 9 (A and B). 

 B. 



A. A side view of the tliree bones of the pelvic girdle of an old adult Cacopus. It 

 will be seen that the boundary of the pubis is indistinguishable ; letters as in 

 test-fig. 8 (A andB). 



B. A transverse section through the same pubis which suggested ossification. 



A., mass of degenerate cartilage at the symphysis: B., supposed network of 

 bony tissue; C, degenerating cartilaginous matrix; V., pi'obably a passage for 

 a blood-vessel. 



which, if real, would be another anticipation of what occurs 

 normally among the higher vertebrata. In older specimens the 

 ilium and the ischium appear to gradually encroach upon it till, 

 at last, in very old ones, it becomes indistinguishable from either 

 of them , both in its area and in its appearance (text-fig. 9 A an d B) . 

 This suggests that, while there may be an ossification of the same, 

 it has no separate centre, and that the process of substitution 

 progresses from the adjacent boundaries of the ilium and the 

 ischium. Sections through such a pubis after decalcification with 

 picric acid show a structure which may be interpreted as an 



