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.1°° 
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 stup- 
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 
*°Orr: A Theory of Development and Heredity. New York, 
Macmillan, 1893. P. 127—128. 
+90 g. Ibid. P. 124. 
