First, with regard to Brown-Séquard's results other than the production of transmitted epilepsy, Weismann allows that the hypothesis of microbes can scarcely apply. In order to meet these results, therefore, he furnishes another suggestion--viz. that where the nervous system has sustained "a great shock," the animals are very likely to bear "weak descendants, and such as are readily affected by disease." Then, in answer to the obvious consideration, "that this does not explain why the offspring should suffer from the same disease" as that which has been produced in the parents, he adds--"But this does not appear to have been by any means invariably the case. For 'Brown-Séquard himself says, the changes in the eye of the offspring were of a very variable nature, and were only occasionally exactly similar to those observed in the parents.'" Now, this does not appear to me a good commentary. In the first place, it does not apply to the other cases (such as the ears and the toes), where the changes in the offspring, when they occurred at all, _were_ exactly similar to those observed in the parents, save that some of them occasionally occurred on the _opposite_ side, and frequently also on _both_ sides of the offspring. These subordinate facts, however, will not be regarded by any physiologist as making against the more ready interpretation of the results as due to heredity. For a physiologist well knows that homologous parts are apt to exhibit correlated variability--and this especially where variations of a congenital kind are concerned, and also where there is any reason to suppose that the nervous system is involved. Moreover, even in the case of the eye, it was always protrusion that was caused in the parent and transmitted to the offspring as a result of injuring the restiform bodies of the former; while it was always partial closure of the eyelids that was caused and transmitted by section of the sympathetic nerve, or removal of the cervical ganglia. Therefore, if we call such effects "diseases," surely it _was_ "the same disease" which in each case appeared in the parents and reappeared in their offspring. Again, the "diseases" were so peculiar, definite, and localized, that I cannot see how they can be reasonably ascribed to a general nervous "shock." Why, for instance, if this were the case, should a protruding eye never result from removal of the cervical ganglia, a drooping eyelid from a puncture of the restiform body, a toeless foot from either or both of these operations, and so on? In view of such considerations I cannot deem these suggestions touching "microbes" and "diseases" as worthy of the distinguished biologist from whom they emanate.