26 PHYSIOLOGICAL SERIES. 



brittle, rendering it even difficult to be cut with a saw, without 

 its chipping into pieces. That part which contains the immediate 

 organ is by much the hardest, and has a very small portion of 

 animal substance in it ; for when steeped in an acid, what remains 

 is very soft, almost like a jelly, and laminated. The bone is not 

 only harder in its substance, but there is on the whole more solid 

 bone than in the corresponding parts of quadrupeds, it being thick 

 and massy." John Hunter, On the Structure and (Economy of 

 Whales, Phil Trans. 1787, Ixxvii. p. 432. 



Hunterian. 



A. 95. A section of the tympanic bone of a Whalebone Whale 

 (Balvena my sticet us], similarly treated. 0. C. 116. 



Hunterian. 



A. 96. A portion of the solid part of a Human femur, which has 

 been steeped in an acid, dried, and preserved in oil of 

 turpentine, to show the animal part. 0.0. 117. Hun/eriau. 



Development and Growth. 



The following preparations are from the common Hog (Sus 

 scrofa), and are the results of experiments made by feeding 

 that animal on the root of madder (R-ubia tiuctontm), but they 

 have now lost their colour. 



A. 97. The skull of a young Pig, slightly tinged. 0. (J. 190. 



Hunterian. 



A. 98. A larger skull, more strongly coloured. 0. (J. 11)1. 



Hunterian. 



A. 99. The right side of the lower jaw, in which the dentine of 

 the teeth has retained more perfectly the red colour, whilst 

 the enamel is of its ordinary whiteness ; [a circumstance 

 which was remarked by Mr. Belchier, the discoverer of 

 this property of madder. Philos. Trans. 1736, xxxix. 

 p. 287.] 0. C. 192. Hunterian. 



A. 100. A longitudinal section of the humerus. The madder 

 appears to have been remitted a short time before death, as 

 there is a thin layer of uncoloured bone deposited on the 

 external surface. 0. C. 193. Hunterian. 



