88 DROSERA ROTUNDIPOLIA. [Chap. VI. 



mutton-chop bone on a third leaf. These leaves soon be- 

 came strongly inflected, and remained so for an unusual 

 length of time; namely, one leaf for ten and the other two 

 for nine days. The bits of bone were surrounded all the 

 time by acid secretion. When examined under a weak 

 power, they were found quite softened, so that they were 

 readily penetrated by a blunt needle, torn into fibres, or 

 compressed. Dr. Klein was so kind as to makQ sections 

 of both bones and examine them. He informs me that both 

 presented the normal appearance of decalcified bone, with 

 traces of the earthy salts occasionally left. The corpuscles 

 with their processes were very distinct in most parts; but in 

 some parts, especially near the periphery of the hyoidal bone, 

 none could be seen. Other parts again appeared amorphous, 

 with even the longitudinal striation of bone not distinguish- 

 able. This amorphous structure, as Dr. Klein thinks, may 

 be the result either of the incipient digestion of the fibrous 

 basis or of all the earthy matter having been removed, the 

 corpuscles being thus rendered invisible. A hard, brittle, 

 yellowish substance occupied the position of the medulla in 

 the fragments of the hyoidal bone. 



As the angles and little projections of the fibrous basis 

 were not in the least rounded or corroded, two of the bits 

 were placed on fresh leaves. These by the next morning 

 were closely inflected, and remained so, the one for six and 

 the other for seven days, therefore for not so long a time as 

 on the first occasion, but for a much longer time than ever 

 occurs with leaves inflected over inorganic or even over many 

 organic bodies. The secretion during the whole time col- 

 oured litmus paper of a bright ro<l; but this may have been 

 due to the presence of the acid superphosphate of lime. 

 When the leaves re-expanded, the angles and projections of 

 the fibrous basis were as sharp as ever. I therefore concluded 

 falsely, as we shall presently see, that the secretion cannot 

 touch the fibrous basis of bone. The more probable explana- 

 tion is that the acid was all consumed in decomposing the 

 phosphate of lime which still remained; so that none was 

 left in a free state to act in conjunction with the ferment on 

 the fibrous basis. 



Enamel and Dentine. As the secretion decalcified or- 

 dinary bone, I determined to try whether it would act on 



