“aa 
; 
3 
“ 
WB On So of Nemertes and Planarie. 
ranks oe highest. 
fext to the entire animal kingdom we have the four great pri- 
mary Efions, the division of Vertebrata, the division of Articu- 
lata, the division of Mollusca and the division of Radiata, and 
these four divisions are characterized by the nervous system 
chiefly. ‘The plan of structure of the nervous or sensitive system 
giving these divisions and these divisions exclusively, its impor- 
tance is of a secondary degree. For the nervous system has not 
yet been materially demonstrated in all the Radiata, whilst the 
nutritive system is to be seen everywhere. Not that I deny the 
sensitive system to any animal even where it has not been 
shown. There exists among the lower Radiata a homogeneity of 
substance which is perhaps “the only obstacle to its discernment ; 
nevertheless the digestive system being everywhere distinct, this 
latter must have the preéminence. 
It has the preéminence because it gives us the unity of the 
kingdom as we have also this unity in the perfect eer cece of 
all eggs at an early period of their history. In the animal the 
first substance which is formed is the vitellus or tole it is the 
i is of the future being, it is, as Prof. Agassiz has observed, 
e being itself. Out of the Yolk the nervous system originates 
as well as all other parts of the organism, so that in an embryo- 
classification of animals. It plays the highest part by its imma- 
terial essence in the human species But here we leave the 
boundary of the animal kingdom and therefore the classification, 
which i igi our object, to enter another kingdom, the kingdom of 
hought 
The nutritive system being the index of animality we see all 
animals equally compelled to take food; this is the essential con- 
dition of their existence. 
The nervous system being the fundamental basis of the pri- 
mary divisions, it gives to each division a special immaterial ten- 
dency so long ‘taught by Prof. Agassiz. Now as there are four 
divisions there are also four of these tendencies. And as soon 
amongst them. ‘This is a natural consequence since the nervous 
system overrules the division and its dominion is of a spiritual 
character. 
The nervous system stamps upon the cam their zoological 
form as the symbol of their diverse tendency. We shall see 
er 
