252 GROWTH PRINCIPLES AND THEORY 2 



correspond to that of a nidifugous species; behaviorally, however, he is nidicolous, 

 remaining under parental care for a long time and so having the opportunity 

 of a uniqvie psychological development. 



According to the principle mentioned (p. 243f), the quantitative increase in 

 brain size is connected with basic qualitative, anatomical and histological, 

 changes (Rensch, 1958). This particularly applies to the development of Broca's 

 center (motor speech center), lacking in subhuman species and granting to man his 

 unique abilities, language, concept formation, and symbolism (Bertalanffy, 1956). 



This example shows again that analysis of growth may lead to basic problems 

 and insight in biology and beyond. It is hardly an exaggeration to state that the 

 problem of growth is a focussing point where the most fundamental problems 

 of biology, from the biophysical bases of the phenomena of life up to the questions 

 of human behavior, converge and intersect. 



