44 



THE MUSEUM. 



and Hawks prey on the Murres to a 

 considerabe extent""'' 



When the time came for us to take 

 leave of the island, in justice to the 

 benevolence of our host, we partook 

 heartily of the feast of boiled Murre's 

 eggs, a delicacy of which those of the 

 "Far East" know not the delights! 

 The penalty was paid later when we 

 set sail in a small fishing boat for 

 "land" and after seven and a half 

 hours' on the briny deep the lights of 

 the metropolis hove in sight and our 

 enjoyment and miseries alike were at 

 an end. 



Natural Preservation of Leaves, 



Ferns, and other Vegetable 



and Animal Remains. 



J. HoBART Egbert, A. M., M. D.Ph.D. 



During a recent trip through south- 

 western Missouri the writer found a 

 most interesting deposit of calcareous 

 tufa and secured a number of beauti- 

 ful specimens. Calcareous tufa is 

 a rather widely diffused mineral owing to 

 the large number of calcareous springs 

 — in the neighborhood of which it is 

 most frequently found. A description 

 of the deposit in question may serve as 

 an interesting key to similar mineral 

 formations and also render the explan- 

 ation of our observations and analysis 

 more entertaining. 



Well up in the mountains of Cedar 

 Co., Missouri, near the border of Polk 

 Co. we found an insignificant little- 

 spring, the water of which after reach- 

 ing the surface incrusts animal and 

 vegetable remains and congeals masses 

 of dried leaves and other debris over 

 which it flows, into a stoney mass. 



* "Birds atul Efrcr.s From the Farallone Is- 

 uiids," l)y \\;iIt«M- F. Ui-y;iiit. 



The water emanating from the spring- 

 flows down a steep incline and seems 

 to make its most abundant mineral de- 

 posit about twenty-five feet from the 

 spring. The process of incrustation 

 takes place quite rapidly — it simply 

 being necessary for a bunch of dried 

 leaves, or other vegetable or animal 

 debris, to remain in a pool of the water 

 or in the current of its flow a few 

 months ere the entire mass is solidi- 

 fied — each particle of vegetation, etc. 

 entering into the mass, preserving its 

 characteristic form and outline. The 

 process, as I observed it at intervals 

 during a period of five weeks on a sel- 

 ected bunch of dried leaves, begins by 

 a slimy deposit on the surface of the 

 dried vegation, which deposit continues 

 to increase in size and density until 

 each leaf is well preserved in a hard 

 and somewhat thickened condition — its 

 outline being maintained, even to min- 

 ute detail. All leaves and debris that 

 remain in the water-course — which has 

 no definite boundaries but spreads out 

 over the hard soil of the mountain side 

 — are likewise treated and those that 

 are collected in masses become united 

 together by a spongy deposit which ul- 

 timately dries and hardens. Thus in 

 a single mass one may find leaves of 

 all the trees common to the vicinity — 

 oak, ash, sycamore, etc. ; also ferns, 

 broken twigs, and feathers of birds. 



As already mentioned this mineral 

 deposit is known to geologists as cal- 

 careous tufa or tufaceous limestone. 

 In composition it is nearly identical 

 with common hmcstone and marble, 

 but is distinguished by its spongy and 

 porous structure. A careful examina- 

 tion of the deposit we have just de- 

 scribed shows it to consist almost en- 

 tirely of carbonate of h'me, \\-ith a 



