IN his reply to a criticism which appeared in NATURE, Prof. Struthers alluded to a question of considerable interest to evolutionists, viz., whether or not the presence of useless organs â proves too much for the argument.â ^* The difficulty is one often met with, and has been well stated by Prof. Huxley, thus :â â Prof. Haeckel has invented a new and convenient name, â Dysteleology,â for the study of the â purposelessnessesâ which are observable in living organismsâ such as the multitudinous cases of rudimentary and apparently useless structures. I confess, however, that it has often appeared to me that the facts of dysteleology cut two ways. If we assume, as evolutionists in general do, that useless organs atrophy, such cases as the existence of lateral rudiments of toes, in the foot of a horse, place us in a dilemma. For, either these rudiments are of no use to the animalâ in which case, considering that the horse has existed in its present form since the pliocene epoch, they surely ought to have disappearedâ or they are of some use to the animal, in which case they are of no use as arguments against teleology,â &c.â