MEMOIRS OF THE NATIONAL ACADEMY OP SCIENCES. 9 



7° Reaumur or 47°.S Fahr. That of Mammoth Cave is a little higher; whether the mean temperature 

 of Carniola is a little lower thau that of Kentucky, we have not the means of stating. 



" Before proceeding further, it may be well to speak of the temperature of Mammotli Cave. It 

 has been roughly estimated that 12,000,000 cubic yards of limestone have been displaced by this 

 immense excavation ; and the importance occurred to me of ascertaining exactly the temperature of 

 such a body of subterraneous air. On inquiry I learned that this had never been accurately done. 

 Hence I made a series of observations in 1878, that satisfied me of the need of still more careful 

 work. Accordingly, in 1881, armed with two staudard thermometers,-oue a Casella from the Kew 

 Observatory, England, and the other a Green from the Winchester Observatory at New Haven, 

 Connecticut, I took a number of observations with the utmost care. Among my conclusions were 

 the following: That the highest degree reached at any time in any part of Mammoth Cave is 5G° 

 Fahr., and the lowest 52=1° Fahr. ; the mean for summer being 54°, and for winter 53°. The latter 

 is probably the temperature of the earth's crust in the region where this cave is located. 



"The above conclusions are confirmed by the readings of an ordinary thermometer placed by 

 Mr. Klett in the Rotunda, and left there till it was, so to speak, acclimated. This gentlemau 

 reports, as the result of almost daily inspection by himself or the guides, that during the period 

 of six mouths the mercury did not rise above 54* nor fall below 53° Fahr., the fair inference being 

 that there was not at any time a variation of more than one degree ! "* 



FAUNA OF MAMMOTH CAVE. 



Infusoria: 



Vibrio and still ruo.re minute bacterium-like organisms in tightly-corked water from Mammoth Cave, 



opened at Salem, Massachusetts, 1874. 

 Chilomonas emarginata Ehr. River Styx (Tellkampf). 

 Chilodon cucullus Ehr. ? 

 Syneda ulva Ehr. 



Monas 2 sp. Serena's Bower (Tellkampf). 

 Colpoda ? . Wandering Willie's Spring. 

 Nassula f or Prorodon ? . Wandering Willie's Spring. 

 Bodo. Serena's Bower (Tellkampf). 



Vermes : 



Dendroocelum percceeum Pack. In Skater's Brook, Richardson's Spring, and other pools. 

 A uematoid worm, parasitic in the larva of Adclops liirtus. (Hubbard.) 



chambers very far removed from the entrance, where thick darkness reigns throughout the day, winter and summer 

 alike, averages 47°. 8 F., and is influenced neither by the time of year nor the time of day. To this is due the fact that 

 in the deepest caves the small number of Arthropods inhabiting them do not hibernate, and that many species belong- 

 ing to the middle cave regions are found in the innermost parts of the caves (Anophthalmns, Adelops, Thysanura, 

 etc.). The Arthropods native to the outer regions of the caves (such as species of Sphodrus, Homalota, Quedins, 

 Thysanura, Scolopendrse, etc.), like their out-of-door relatives, hibernate at the beginning of cold weather under 

 sticks and stones, in moss, etc. 



* As this is a matter that has been under dispute, former observations by scientific observers having agreed on 59° 

 Fahr. as the correct temperature, I give below a table of my main observations, which were most carefully made 

 with practically perfect instruments on the 13th and 15th days of August, 1881 : 



Deg. Fahr. 



At the hotel on the hill the mercury indicated 92 



At the mouth of the cave (at noon) 65-i 



Deg. Fahr 



At the Bottomless Pit : 



Top , 54 



At the mouth of the cave (7 p. m.) 60 Midway 56 



At the Iron Gate, 100 yards within, where the cur- 

 rent is strongest 52^ 



In the Rotunda (1,000 yards within) 53 



In Audubon's Avenue 54 



In Little Bat Avenue 54 



In the Gothic Avenue (oldest and driest portion).. 50 



In Richardson's Spring (in the water) 54 



In the Arched Way ' 544 



At the bottom 53 



In the Mammoth Dome : 



Top, 250 feet above bottom 54 



Midway .... 53 J 



Bottom 53 



At the Echo River: 



In the water 55 



In the air 5C 



Where it empties into Green River 58 



