86 DROSERA ROTUNDIPOLIA. [Chap. VL 



of elastic tissue, which is never acted on, could hardly be 

 said to be in a liquetied condition. 



Some areolar tissue free from elastic tissue was next 

 procured from the visceral cavity of a toad, and moderately 

 sized, as well as very small, bits were placed on five leaves. 

 After 24 hrs. two of the bits were completely liquefied; two 

 others were rendered transparent, but not quite liquefied; 

 whilst the fifth was but little affected. Several glands on 

 the three latter leaves were now moistened with a little saliva, 

 which soon caused much inflection and secretion, with the 

 result that in the course of 12 additional hrs. one leaf alone 

 showed a remnant of undigested tissue. On the discs of ^e 

 four other leaves (to one of which a rather large bit had been 

 given) nothing was left except some transparent viscid 

 fluid. I may add that some of this tissue included points of 

 black pigment, and that these were not at all affected. As a 

 control exi)eriment, small portions of this tissue were left in 

 water and on wet moss for the same length of time, and 

 remained white and opaque. From these facts it is clear 

 that areolar tissue is easily and quickly digested by the se- 

 cretion ; but that it does not greatly excite the leaves. 



Cartilage. Three cubes (^ of an inch or 1.27 mm.) of 

 white, translucent, extremely tough cartilage were cut from 

 the end of a slightly roasted leg-bone of a sheep. These 

 were placed on three leaves, born by poor, small plants in 

 my greenhouse during November; and it seemed in the 

 highest degree improbable that so hard a substance would be 

 digested under such unfavourable circumstances. Neverthe- 

 less, after 48 hrs., the cubes were largely dissolved and con- 

 verted into minute spheres, surrounded by transparent, very 

 acid fluid. Two of these spheres were completely softened 

 to their centres; whilst the third contained a very small 

 irregularly shaped core of solid cartilage. Their surfaces 

 were seen under the microscope to be curiously marked by 

 prominent ridges, showing that the cartilage had been un- 

 equally corroded by the secretion. I need hardly say that 

 the cubes of the same cartilage, kept in water for the same 

 length of time, were not in the least affected. 



During a more favourable season, moderately sized bits of 

 the skinned ear of a cat, which includes cartilage, areolar 

 and elastic tissue, were placed on throe leaves. Some of the 



