Chap. i. 
RUDIMENTS. 
27 
a tes to remove some of the molar teeth of children, 
! | S ^ le Jaw does not grow large enough for the perfect 
c e ' elopment of the normal number. 
Vith respect to the alimentary canal I have met 
I 1 an account of only a single rudiment, namely the 
' ei mifor m appendage of the ceecum. The caecum is 
a branch or diverticulum of the intestine, ending in a 
‘-ue-siic, and it is extremely long in many of the 
.° Wer vegetable-feeding mammals. In the marsupial 
'"ala it i s actually more than thrice as long as the 
'°le body . 34 It is sometimes produced into a long 
S r adu a lly-tapering point, and is sometimes constricted 
P ai 'ts. It appears as if, in consequence of changed 
. °y habits, the cmcum had become much shortene l 
'arious animals, the vermiform appendage being left 
a rudiment of the shortened part. That this ap- 
II m age is a rudiment, we may infer from its small 
-»-d from the evidence which Prof. Canestrini 36 has 
ected of its variability in man. It is occasionally 
j * e a hsent, or again is largely developed. The passage 
sometimes completely closed for half or two-thirds of 
8 ® n gth> with tlie terminal part consisting of a flat- 
solid expansion. In the orang this appendage 
in man it arises from the 
and is commonly from four 
being only about the third 
- . — — Not only is it useless, but 
som etimes the cause of death, of which fact I 
hard ! atdy ^ lear< l two instances: this is due to small 
< Jodies, such as seeds, entering the passage and 
causing inflammation » 
S on § and convoluted . 
*he short case urn, 
?, VQ _ inches in length, 
au inch in diameter. 
3f 
31 i -faatoray of Vertebrates,’ vol. iii. pp. 416, 434, 441. 
»» n c dell!l Soo. d. Nat.’ Modena, 1867, p. 94. 
blondes ’ Jon ai ,*‘ ns (“Do l’Unite Organiquc,” in ‘Revue des Deux 
e , 1862, p. 1G), and Hackel (‘Generelle Morphologie,' 
