Attempts at acclimating Amblyopsis in outside waters have so far failed.[K] A few were placed in Turkey Lake, Indiana. They were surrounded by a fine wire net, to keep off other fishes. They died in a few days, as the result of attacks of leeches, _saprolegnia_, or fish mold, and from unknown causes. Others were kept in an elongated box sunk into the ground, where fresh spring water flowed through it constantly. _Saprolegnia_ sooner or later destroyed all of them. They live longest in quiet aquaria, where the water is rarely changed. The young I have secured died, with one exception, within a few weeks. The difficulty of rearing the young is not at all insurmountable. They eat readily. Their aquaria must be kept free from green plants, and have a layer of fine mud, with a few decaying leaves, in the bottom. They will feed on minute crustaceans and other micro-organisms. When they have reached a sufficient size, examples of Asellus are greedily devoured. Fish mold is the bane of the larvæ. Many of them were found with tufts of the _hyphæ_ growing out of their mouths and gill openings. [K] Since the above was written an apparently successful attempt has been made to colonize them in a pool at Winona Lake. A record of this colony will be published later. THE MAN OF SCIENCE IN PRACTICAL AFFAIRS. BY F. W. CLARKE. The human mind is addicted to the creation of types, a process which implies classification and generalization of a somewhat low order. Some prominent feature of the thing classified is selected for emphasis, and there is often a degree of exaggeration which leads, in the end, to caricature. John Bull, Brother Jonathan, the Jew of the comic papers, and the stage Irishman are examples of this tendency. So, too, a profession or occupation is summed up in one conventional character, with a little truth distorted as if seen reflected from the surface of a curved mirror. The likeness is there, but unlike the reality. The individual embodiment of the type is rarely, if ever, encountered.