LECTURE VIII. 

 THE CELL AND HEEEDITY. 



First animals (protozoa) one-celled. Consisting of 

 a sac rilled with protoplasm, the physical basis of life. 

 Qualities of protoplasm. Within the protoplasm, the 

 nucleus, composed chiefly of loops and bands of chro- 

 matin. The chromatin presides over the development 

 and differentiation of the protoplasm, action itself be- 

 ing a function of the protoplasm. Action of the astern 

 or attraction spheres. Limitation in size of protozoa. 

 Cell division of protozoa. Rapidity of multiplication. 

 One would fill the bulk of the sun in a month if all 

 the conditions were favorable. 



Law of Mutual Aid. (1) Its beginning shown in 

 aggregation of cells. So-called immortality (Unsterb- 

 lichkeit) of protozoa not immortality of the fabled 

 demigod Ares, who when hurt " bellowed like ten 

 thousand bulls," but could not die. They die only 

 when the activity of their protoplasm is checked by 

 outside influences. Natural death not known to them. 

 Must be fully alive or fully dead. No intermediate 

 stage. Aggregation of cells leads to increased size, 

 specialization of parts, sensitiveness, intelligence, and 

 natural death. Natural death a necessary resultant 

 of differentiation of structure. Simplicity, ignorance, 

 and immortality in the process of Evolution exchanged 

 for sensibility, pain, and death. How "Brahma fell 



