FISCHER ON THE PELYIS OP THE MAMMALIA. 19 



nachher sehr breit und bildet mit dem sclimalen Schambeine eine selir grosse 

 ingliclite Oeffnung." 



The symphysis of the pubis is always osseous in the beaver (the symphysis 

 of the bones of the pubis is sometimes found osseous not only in the horse, 

 but also in the aged dog, and in the fox, which seems to prove that in these 

 animals, during parturition, there is no force acting against this symphysis 

 as in woman. Autenreith.') The foramina ovalia are very large in this order, 

 especially in the common squirrel. The ossa innominata in the glires suffi- 

 ciently resemble each other, in as far as regards the os ilium : for they are 

 narrow, convex on their external surface, so as to appear obtusely carinated, 

 with an internal concave surface, almost canaliculated towards the apex, and 

 bent outwards with a rounded subacute summit. The hare alone has the 

 superior extremity of the os ilium larger and less convex than the rest. The 

 os ilium of the rabbit is shorter, but broader, according to the size of the 

 animal. There exists, however, this principal difference : that in the hare 

 and in the rabbit the symphysis of the pubis is very long, so as to form a 

 semi-canal, in the hare but little turned upwards ; and that the branches of 

 the os ischium meet under an acute angle, and the three-sided tuberosities of 

 the os ischium much extended backwards, so that there is a deep fissure of 

 the pelvis between them. On the other hand, as has been mentioned above, 

 the mures have a very short symphysis, and the branches of the os ischium 

 not only unite at a right angle in a very slender tuberosity, but also almost at 

 the same angle with the descending branches of the os pubis. The squirrel 

 holds, as it were, a medium between the mus and the hare ; it has a 

 distinct tuberosity of the os ischium, but like the rat, it has the branches of 

 the os ischium meeting almost at a right angle. Autenreith. 



Section 19. 6. Ferae. The greatest variety of the bones of the pelvis ex- 

 ists in this artificial order of animals, both as regards size, as between the 

 shrew (sorex fodiens) and the polar bear ; and as regards form, as between 

 the european mole, the lion, and the gigantic didelphis. The os sacrum is 

 composed in most of the ferse of three vertebrae, which number is by no means 

 so constant and frequent in any ether order ;* in some species, however, there 

 are exceptions, as in the didelphis oppossum, and gigantea, in which the sacrum 

 has two vertebra ; in the european mole, and in the ursus arctos, the os sacrum 

 five vertebrae. Blumenbach f says of the os sacrum of the european mole 

 " Beim Maulwurf hat es langst seiner Hinterseite statt der Dornfortsaze einen 

 ununterbrochenen schneidenden Riicken, der dem kleinen Thiere bei seiner 

 unterirrdischen Lebenstart besonders aber bei der Weise, wieer die mit den 

 Vorderfiissen losgegrabene Erde mit den Hinterfussen. hinter sich wirft, sehr 

 zu statten Kommt." Daubenton J says " The first vertebra of the sacrum 

 has no spinous process ; those of the remaining four are united to each other, 

 forming an osseous crest." 



Section 20. In nearly all the ferse the tail is long, and the coccygeal 

 vertebra? are numerous ; the European mole has 12, the common weasel 14, the 

 stoat 16, the fox and the shrew 19, the civet cat 22, the common cat and the 

 leopard 23, the common otter 25, the genett cat 28, and the opossum 29. 

 The superior of these vertebrae are perforated by a canal for the spinal mar- 



t T. F. Blumenbach, Beschreibung der Knochen. p. 305. 

 | Histoire Naturelle, Tom. viii. 4, p. 103. 



