that kind proceeding from knowledge demands an activity of the brain rising to the level of reason. On the other hand, the intellect even of the lower animals is sufficient for the modifying and arranging of the particular case according to the existing or appearing circumstances; because, guided by instinct, it has only to fill up the gaps which this leaves. Thus we see ants carry off their larvæ whenever the place is too damp, and bring them back again when it becomes dry. They do not know the aim of this, thus are not guided in it by knowledge; but the choice of the time at which the place is no longer suitable for the larvae, and also of the place to which they now bring them, is left to their knowledge. I wish here also to mention a fact which some one related to me verbally from his own experience, though I have since found that Burdach quotes it from Gleditsch. The latter, in order to test the burying-beetle (Necrophorus vespillo), had tied a dead frog lying upon the ground to a string, the upper end of which was fastened to a stick stuck obliquely in the ground. Now after several burying-beetles had, according to their custom, undermined the frog, it could not, as they expected, sink into the ground; after much perplexed running hither and thither they undermined the stick also. To this assistance rendered to instinct, and that repairing of the works of mechanical tendency, we find in the organism the healing power of nature analogous, which not only heals wounds, replacing even bone and nerve substance, but, if through the injury of a vein or nerve branch a connection is interrupted, opens a new connection by means of enlargement of other veins or nerves, nay, perhaps even by producing new branches; which further makes some other part or function take the place of a diseased part or function; in the case of the loss of an eye sharpens the other, or in the case of the loss of one of the senses sharpens all the rest; which even sometimes closes an intestinal wound, in itself fatal, by the adhesion of the mesentery or the peritoneum; in short, seeks to meet every
