790 



de[)th, ut tlie eiui it is surrounded only by an extremely fine layer 

 of conns tissue. The widened portion of the canal is 1.5 mm. long, 

 the greatest depth measures 0.4 and the greatest breadth 0.18 mm. 

 No folds of the wall, nor any indications of such can be noticed. 

 Cell-remnants are present in the ventriculus. No more spinal ganglions 

 are seen at or near the top of the conns. 



Caniii fmni/iriris. In carnivori the conns does not reach the sacral 

 canal. In the nuddle the lumbal medulla is liearl-shaped on section 

 wiih the blunt point directed backwards. The grey matter is very 

 strongly developed. Owing to the presence of the big commissura grisea 

 the fine septum posterius is very small. The central canal is an 

 irregular round, frequently it is a distinct pentagon on section, the 

 epithelium is poorl}' developed and even lost in several places; 

 many remnants of it are found in the central canal, which is also 

 wholly, or nearly wholly, obliterated, its depth and breadth are 

 practically ecpuil, the diameter measures 0.17 mm. in the strongly 

 developed motor horns we find large cells ventrally oidy. The pos- 

 terior horns touch a large part of the back wall of the conus, the 

 border zone is not so sharply marked as in the Ungulates. In this 

 area too a few large cells occur. In general the medulla is poorer 

 in cells than the sacral medulla of ruminants (fig. 17). Further 

 back the conns becomes kidney-shaped on section and the canal 

 measui'es more in width than in depth, the broad base sometimes 

 arched, sometimes flat, measures 0.250 mm. and the depth 0.125 mm. 

 Here we find traces of folding at the base and sometinses also 



Fia;. 17. Cauls familiaris. 



Fia:. 18. Felis catis domest. 



above. Now the formation of the ventricle commences, the canal 

 deepens towards the back; at first it is pointed in front and rounded 

 at the back, so that the whole in section becomes pear-shaped ; 

 later the base also rounds off so that it becomes an elongated oval, 

 after which it gradually decreases. In three dogs the measurements 

 were as follows: from the number of transverse sections (he 



