384 



Popular Science Monthly 



Why Does the Heart Stop Beating 

 at Death? 



THE question, "Why does a man or an 

 animal die?" has been answered, 

 "Because the heart stops beating." But 

 any hunter or fisherman who has dressed 

 his own catch can testify to the fact that 

 the heart does not stop beating at the 

 moment of the animal's death. Often it 

 will continue to pulsate rythmically for 

 several minutes after it has been removed 

 from the carcass. The most recent answer 

 to the "Why?" of this is that the heart 

 muscles themselves possess the inherent 

 quality of contraction and will contract, or 

 beat, just as soon as or as long as the 

 conditions of environment are right. That 

 is their business and they can no more 

 refrain from doing it under the right con- 

 ditions - than a rose could help giving out 

 its fragance. 



In recent experiments it has been found 

 that heat is the principal element. necessary 

 to the development of heart muscles and 

 their subsequent action. It is possible tO' 

 grow the heart muscles of a warm-blooded 

 animal in an incubator. During this 

 growth a single muscle cell has been ob- 

 served to develop and wander away from 

 the mother cell and begin to beat of its own 

 accord. Again, several individual cells may 

 attach themselves to each other in a colony 

 and beat rythmically together as long as 

 the environment is favorable. 



But let the temperature of the incubator 

 be materially reduced and the action of 

 the heart muscles becomes sluggish. Re- 

 duce the temperature still further and 

 gradually the rythmic action ceases al- 

 together. The cells cease to perform their 

 natural function because their environment 

 is no longer right. In other words, they 

 die because they are cold. According to 

 this theory, the heart muscles, could live 

 on independently of a body, if kept at the 

 proper temperature for their best^develop- 

 ment. 



A Land Ride for Whales 

 in South Africa 



AHUGE motor-truck equipped with 

 flanged wheels for use on a standard- 

 gage railroad has come to the rescue of a 

 whaling company in South Africa and has 

 solved its transportation problem. The 

 whales are carried by truck from the shore 

 and are transported to the factory to be 

 treated for the extraction of oil and other 

 products. 



The whales are hoisted on the truck by 

 means of derricks and when once in place 

 on the truck body they are securely lashed 

 by chains. The truck is sixty-five feet long. 

 It has a capacity of one hundred and sixty 

 thousand pounds. The six-wheeled sup- 

 ports for the truck body keep the axle loads 

 down to the required limits and insure the 

 necessary flexibility over the railroad line. 



Transporting whales in South' Africa by means of a special motor-truck railroad car. Whales 

 weighing as much as eighty tons can be transported in this manner from the shore to the 



