Page:Popular Science Monthly Volume 18.djvu/542

526 the case which varies very greatly with individuals, and even varies with the nervous states of the same individual. And this suggests the further thought that a careful comparison of individuals relatively to their illusion-capacity might elicit some interesting and perhaps valuable facts concerning the relation between the states of brain-organization and the sensations of the more highly specialized organs of sense.—Brain.

 

UCH may be said in favor of the hypothesis of the progressive development of all the stable forms of matter by a true process of evolution from antecedent states. Indeed, in the higher forms of matter, in those which we know to be of composite constitution, this process is more or less thoroughly understood. Most of the objects which surround us, whether organic or inorganic, are known to consist of a great number of elementary parts of the same size and form which are aggregated in definite ways to form the general mass which each such object presents. These particles, which are alike for all parts of the same object or species of object, are unlike for different objects. Each object is an aggregate of elements of the same species, and these elements are the units of aggregation. All aggregates which have been thus far resolved into these units have confirmed this law. What is known, however, of the higher aggregates of matter is sufficient to establish another law, viz., that such aggregates are the result of the successive recompounding of units of aggregation of descending orders. The units of aggregation of aggregates of the higher orders are compounds of lower units. This is physically proved to be true of all aggregates of known composition.

In biology we have the individuals of various orders, both animal and vegetable, in which the lower forms are taken up bodily and made to enter as integral units into the higher forms. Not only are all animals and plants compounded of innumerable cells as ultimate biological units, but the earlier forms, which are aggregations of cells, are repeated as units in the higher forms. The tape-worm is an animal of the third order, the cell being taken as the first, but its segments are so feebly integrated that they possess all the essential characteristics of perfect animals. In the higher Annulosa, the integration is more complete, but the composite character is still evident. In the Vertebrata, the process of coördination has proceeded so far that only the 