Literary Notices. Ixvii 



acter of the greatest selective importance ; but of still greater impor- 

 ance in this case, as well as in the second case, is the gain in the pre- 

 cision of the movement in the case of the reflex. Almost any oft-re- 

 peated reflex action can be performed not only more promptly but 

 more perfectly without the aid of consciousness than with such inter- 

 ference. But a consideration of more importance than any of the pre- 

 ceding is the principle of mental economy. It is a familiar pedagog- 

 ical maxim that education consists largely in the training of the lower 

 centres so as to enable them to perform the mechanical duties of life 

 unconsciously, thus leaving the mind free for the performance of higher 

 duties. Mr. Romanes seems not to have recognized this when he 

 says, " As long as the animal preserves its brain, it will likewise pre- 

 serve its balance, by the exercise of its intelligent volition. And, if 

 the brain were in some way destroyed, the animal would be unable to 

 breed, or even to feed ; so that natural selection can never have had 

 any opportunity, so to speak, of developing this reflex mechanism in 

 brainless frogs. On the other hand, as we have just seen, we cannot 

 perceive how there can ever have been any ration d'etre for its develop- 

 ment in normal frogs — even if its development were conceivably possi- 

 ble by means of this agency. But if practice makes perfect in the race, 

 as it does in the individual, we can immediately perceive that the con- 

 stant habit of correctly adjusting its balance may have gradually devel- 

 oped, in the batrachian organization, this non-necessary reflex." To 

 this it need only be added that the reflex is normally present and is in 

 constant use as a reflex in the uninjured body and that in this case, at 

 least, it is by no means useless. The other illustrations adduced seem 

 to me open to similar criticisms. Now, I do not mean to imply that no 

 reflexes and no instincts are due to lapsed intelligence ; but many re- 

 flexes and some instincts are certainly not so derived and Mr. Romanes' 

 illustrations for the present discussion would seem to have been most 

 unfortunately chosen. 



Among the experimental evidences of the inheritance of acquired 

 characters, the experiments of Brown-Sequard on guinea-pigs stand out 

 as preeminent. They are, in fact, almost the only experiments which 

 can be cited thus far which can be regarded as in any way decisive. 

 The now famous experiments of Brown-Sequard are described and their 

 results, so far as they are germain to the present discussion, are out- 

 lined, together with Weismann's comments upon them. But of far 

 greater interest is the account of the long-desired verification of Brown- 

 Sequard's experiments undertaken by Mr. Romanes himself. The first 

 series of experiments was begun over twenty years ago and then yielded 



