36 AGE, GROWTH, AND DEATH 



remains were used for various purposes. The pig- 

 ment which is in the liver comes from the destroyed 

 blood corpuscles, and it is believed that the pigment 

 which colours the hair is derived from the same 

 source. The blood corpuscles contain a material 

 which when chemically elaborated reappears as the 

 deposit which imparts to the hairs their colouration. 

 You, of course, are all familiar with the loss of hair. 

 It occurs to everybody, but did you ever think that 

 it means that the hair which has lived has died, and 

 that that hair which was a part of you has been cast 

 off ? That is what the loss of hair means to the bi- 

 ologist the death of a part and the throwing away 

 of it, and it is typical of what is going on through 

 the body all the time. It occurs in the intestines, 

 where the elements which serve for purposes of 

 digestion are continually dying and being cast off. 

 The outer skin is constantly falling off and being 

 renewed, and that which goes is dead. In every part 

 of the body we can find something which is dying. 

 Death is an accompaniment of development ; parts of 

 us are passing off from the limbo of the living all the 

 time, and the maintenance of the life f each individ- 

 ual of us depends partially upon the continual death 

 going on in minute fragments of our body here and 

 there. 



Our next step in this course of lectures will carry 

 us into the microscopic world, and with the aid of 

 the lantern at the next lecture I shall hope to demon- 

 strate to you a little of the microscopic structure of 



