314 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



of the cave and other subterranean streams, and is of a dark 

 color. It lives principally on the bottom, and is exceedingly- 

 quick in its motions. It belongs to the same family as the 

 two species of blind fishes found in the cave. He also ob- 

 tained five specimens of four species of fishes that were in 

 every respect identical with those of the Green River, show- 

 ing that the river fish do at times enter the dark waters of 

 the cave, and when once there apparently thrive as well as 

 the regular inhabitants. A large number of the white blind 

 fishes were also procured from the Mammoth Cave, and from 

 other subterranean streams. In one stream the blind fishes 

 were found in such a position as to show that they could go 

 into daylight if they chose ; while the fact of finding the 

 Chologaster in the waters of the Mammoth Cave, where all 

 is utter darkness, proves that animals with eyes flourish there, 

 and is another evidence that color is not dependent on light. 

 Mr. Putnam found the same array of facts in regard to the 

 cray-fish of the cave, one species being white and blind, while 

 another species had large black eyes, and was of various 

 shades of a brown color. A number of living specimens of 

 all of the above-mentioned inhabitants of the waters of the 

 cave were successfully brought to Massachusetts after hav- 

 ing been kept in daylight for several weeks, showing that all 

 the blind cave animals do not die on being exposed to light, 

 as has been stated. 



THE AGENCY OF ATMOSPHERIC PRESSURE IN CAUSING THE 

 UNION OF THE JOINTS OF THE HUMAN BODY. 



The agency of atmospheric pressure in securing the union 

 of the joints of the body has long been appreciated, although 

 it has been thought that a puncture of the capsule connect- 

 ing the joints, by thus admitting air, would materially affect 

 this action. Professor Aeby, of Berne, however, has an- 

 nounced, as the result of a large number of experiments, that 

 in the greater number and the most important of the joints 

 of the human body the atmospheric pressure is fully adequate 

 to retain the surfaces of the constituent bones in contact, even 

 after the division of all the soft parts, including the capsule. 

 This statement is true of the shoulder, elbow, and wrist, as 

 well as of the hip, knee, and ankle joints, and the experiment 

 succeeds in nearly every natural position of the joint, so that 



