390 ILLUSTRATIVE NOTES. 
Has the insect a brain? It is a disputed question. The nervous appar- 
atus which, in the molluscs, has not found, so far, a centre, tends, it is true, 
in the insect, towards centralization. Two longitudinal strings of nerves, 
which run through the entire length of the body, abut on the nerves of the 
head, which are not massed as in the higher animal. In the wasp, however, 
has been discovered a firm, whitish substance, strongly resembling the brain. 
But this would seem exceptional. Even in the head of insects remarkable for 
their intelligence, you will find only simple nervous ganglions, not differing in 
any respect from those which compose the two threads. 
This inferiority of organization does but render more surprising the 
superiority of the insect in art and sociability to all other animals, even to the 
principal mammals (with a single exception). Here at the highest point of 
the ladder, there at the lowest, it occupies, on the whole, a middle place; and 
1s, as it were, in the scale of existence, an energetic mediator between life and 
death. 
NOTE 7.—Book ii., Chap. i. 
Swammerdam.—We refer to the inaugurator and martyr of our science, the 
creator of the instrument which has enabled men to follow up his discoveries,— 
a great inventor in many senses,—specially for the preparation of anatomical 
specimens. The reader should study his Biblia Nature, in Boerhaave’s edition, 
ornamented with fine illustrations (two vols. folio), and not in the incomplete 
French abridgment, published in the Mémoires of the Academy of Dijon, 
which gives the scientific results, but no trace of the man. 
