— 171 — 
OUS fibrillæ of the vertebrates) and will, in my opinion, explain 
many facts as to its occurrence. If the theory is correct, then, the 
dotted substance must be a principal seat of the nervous activity, 
and — the higher an animal is mentally developed — the more 
complicated and extensive must we expect to find its dotted sub- 
stance ; this is in the fullest harmony with the facts already known. 
We need only refer the reader to the ant, or the bee, to compare 
the extremely complicated and highly developed dotted substance 
of these small inteligent animals, with the dotted substancs of less 
developed insects, or to compare the dotted substance of the insects 
or crustacea with that of annelides, etc. etc. I am sure that my 
readers will very soon arrive at the conclusion, that the more com- 
plicated the structure of dotted substance is — the more highly is 
the animal mentally developed ; in other words, we may conclude 
that the more the inteligence of an animal is developed — the more 
intricate hecomes the iveh or plaiting of nerve-tuhes and fibrillæ in 
its dotted substance; the protoplasmic processes etc. of the ganglion 
cells are of no great importance in this respect. In this manner we 
can explain how it is, that unipolar cells occur in the nervous 
system of animals (e. g. insects and crustacea) which are mentally 
even highly developed; these animals have an extremely intricate 
web of nerve-tubes in their dotted substance, and this web is pro- 
bably the principal seat of inteligence. 
