VIII. THE INHERITANCE OF ACQUIRED CHARACTERS 397 



memory must be required. For this purpose higher animals may 

 possess a certain group of cells, in which the memory is well kept 

 by the repetition of the reversible change, to produce the germ cells. 



2. The Transmission of Acquired Pattern to Germ Cells 



In the case of unicellular organisms, the transmission of the 

 change, given rise to in the protoplasm, to the gene may readily 

 take place, but in multicellular organisms, its transmission to the 

 genes of the germ cell appears at first sight to be impossible, although 

 for the establishment of the inheritance of acquired characters the 

 transmission of the pattern from soma to germinal seems indispen- 

 sable. The writer holds the opinion, however, that this is actually 

 possible, and factors involved in this process are both hormones and 

 virus-like agent as will be mentioned below. 



For a multicellular organism, to exhibit various functions as a 

 single living organism, that is, to behave as an individual, a variety 

 of cells or cell systems involved in the organism must be coordinated, 

 or must work in harmony. This coordination is established usually 

 by two ways. One is by means of substances that circulate in the 

 blood, namely hormones, and the other is by means of impulses that 

 pass along the nerves. As the result of secretions which enter the 

 blood from endocrine glands, what is known as chemical coordination 

 is possible. 



It has been known for a long time that various external influences, 

 especially deleterious agents, applied to higher animals lead to a striking 

 change in the function of endocrine glands. At present, it is generally 

 believed that the endocrine system plays a prominent part in the adap- 

 tive reactions which occur irrespective of the specific nature of the 

 damaging agent-s. The sum of all these non-specific, systemic reactions 

 of the body which enstre upon long-continued .exposure to stress has 

 been termed the "general-adaptation-syndrome" (74). It is charac- 

 terized by a number of morphological and functional change. Among 

 the most prominent of these is the enlargement of the adrenal cortex 

 with increased corticoid-hormone secretion, involution of the thymus 

 and of other lymphatic organs. 



A number of deleterious effects such as reduced atmospheric 

 pressure, extreme heat or cold, severe muscular work, hemorrhage, 

 burns, traumatic shock, and a large variety of drugs, cause histologi- 

 cal signs of increased adrenaline and corticoid hormone secretion. All 

 these phenomena run closely parallel with the general damaging 

 effects of agents and must be regarded as part of the general-adaptation- 



