252 Theories Treating of Inheritance 



in each generation, first cell walls, and then the differ- 

 entiated organs." 189 



From the whole work of Orr it seems to result with- 

 out any possible doubt, that according to his view this 

 non-differentiated part of the protoplasm is present in 

 all the cells of the organism, is everywhere quite similar, 

 and is continuous to the extent that stimulating influ- 

 ences can be transmitted from any given part whatever 

 to all parts of the animal, so that it constitutes a complete 

 physiological unit. 190 



But on the other hand it is never to be seen quite 

 clearly what this investigator understands by this greater 

 complexity of co-ordination. The fact that the nervous 

 system presides over all physiologic activities of the 

 organism makes him think rightly that development also 

 may be dependent on similar nervous phenomena. Only 

 in the nervous system of the organism is clearly to be 

 seen what is to be understood by a greater complexity 

 of nervous co-ordinations, because it is constituted by 

 numberless points, distinct from one another and con- 

 nected with one another in more or less complicated ways 

 by direct or indirect nerve tracts. In undifferentiated 

 protoplasm on the contrary, which remains always en- 

 tirely similar in the most different parts of the body, 

 and a fortiori in that infinitely small part contained in 

 the germ cells, one could not conceive in what these sup- 

 posed nervous co-ordinations and this ever greater com- 

 plexity of co-ordinations could consist, and what their 

 significance would be. 



The following passages do not clear up any of the 



i89 



9Q rr . p^ Theory of Development and Heredity. New York, 

 Macmillan, 1893. P. 127128. 

 "E. g. Ibid. P. 124. 



