(8) The charge that our immigrants are not completely assimilated, or are not assimilated at all, is one of the most frequent and gravest complaints made against our present immigration situation. It is made to include—as, indeed, it rightfully does in a sense—all the other arguments against immigration. The term assimilation is almost unfailingly suggested by the mere mention of immigration. But assimilation is a big word, and needs to be used with great caution and understanding. In its general application, assimilation is defined as the “act or process of assimilating, or bringing to a resemblance, conformity, or identity,”[353] or “the act or process of making or becoming like or identical; the act or process of bringing into harmony”;[354] or again, “the action of making or becoming like; the state of being like; similarity, resemblance, likeness; ... the becoming conformed to; conformity with.”[355] It is evident from these definitions that the essence of assimilation is likeness or conformity; this of necessity implies a type to which such likeness approaches. It appears that it would not be incorrect to speak of assimilation when there is nothing more than resemblance; it seems equally clear that _complete_ assimilation involves identity. This is particularly evident in reference to the special application of the term, which is the one generally in mind when it is used, viz. the assimilation of food in the body. In this sense the process is described as “the reformation of biogen molecules by those already existing, aided by food-stuffs.”[356] It is this physiological analogy which underlies the term assimilation when applied to population, and the whole matter may be best understood by keeping that analogy in view. When nutriment is taken into the system of a living organism, it passes through certain processes by which it ultimately becomes an integral part of the physical body of that organism. It is then said to be assimilated. Every suggestion of separate origin disappears, each new constituent entering harmoniously into relation with the others, new and old, and fulfilling its own functions. While it is true that certain food elements contribute particularly to certain portions of the organism, yet the whole is a coördinated unit. Any portion of the food which created disturbance with reference to the body would not be said to be assimilated.