2 12 



How a Cojnplex Ani?nal Uses Food unit iv 



Fig. 213 This pJ:)otograph 

 was taken while the man was 

 donating blood for the third 

 time at a Red Cross Center 

 during World War 11. How 

 was the blood used? Is there 

 still a need for blood dona- 

 tions? 



work of a great physiologist, Karl Land- 

 steiner, who died in 1943. 



Also it was discovered recently that 

 there is a substance in the blood of most 

 people called the "Rh factor." A few 

 people lack it. The name comes from the 

 animal, the Rhesus monkey, used in the 

 experiments which led to the discovery 

 of the substance. If the mother lacks the 

 Rh factor, the development of the un- 

 born child may be interfered with; some- 

 times the child dies. 



When transfusions were first given it 

 was necessary to introduce blood from 

 the donor directly into the patient. Since 

 the first World War, thanks to an im- 

 portant discovery made by a scientist in 

 Argentina, Dr. Luis Agote, we have 

 learned to preserve blood so that the red 

 cells do not die. Now blood can be col- 

 lected and kept in blood banks. 



Using parts of the blood instead of 

 whole blood. At the present time plasma 

 and sometimes serum is used rather than 



whole blood because neither plasma nor 

 serum need be matched. Besides this, 

 plasma has the great advantage that it 

 can be easily dried and readily preserved 

 without spoiling. With the addition of 

 distilled water dried plasma is ready for 

 use. In this kind of transfusion the 

 wounded receive no red blood cells but 

 this is often not as important as you 

 might think because ordinarily the body 

 has a large supply of these in reserve. 

 During World War II most of the blood 

 which was given through the Red Cross 

 was used to produce dried plasma. 



Very recently chemists have gone one 

 step farther. They have learned to sep- 

 arate the proteins in plasma from each 

 other. Professor Edwin Cohn of Harvard 

 University has been a leader in this work. 

 It has been found, for example, that not 

 the whole plasma but only one of its 

 proteins is needed for treating shock. 

 This one protein when separated from 

 the rest will occupy far less space and 



