II. RESEARCHES ON THE REFLEX FACULTY. 



During the last seven years I have published many papers re- 

 lating to the reflex faculty.* Among the facts which I have 

 discovered I will mention the following : 



1. Grainger had found that the act of suckling can be exe- 

 cuted by an animal deprived of its brain. I have found that 

 even after the ablation of both the brain and the cerebellum, 

 newly-born rabbits are able to suckle very well; which is a 

 proof that suckling may be executed by reflex action. 



2. It is commonly affirmed that the reflex power is much 

 stronger in cold-blooded than in warm-blooded animals. This 

 opinion is correct so far as regards the contrast between Mam- 

 mals and Batrachia (the animals usually compared) ; but it is 

 incorrect if Birds are compared with Reptilia and Fishes. It has 

 been said that the higher an animal is in the scale the less it 

 has reflex power. If this be true, we should find more and more 

 reflex power from Mammals to Fishes ; but the real order, ac- 

 cording to my experience is : 1st, Fishes; 2d, Mammals; 3d, Am- 

 phibia and Reptilia ; 4th, Birds ; so that Birds have more reflex 

 power than all the other animals, and Mammals have more than 

 Fishes. Of course, there are exceptions to this rule in the case 

 of particular species ; thus the eel, carp and tench have as 

 much reflex power as many Mammals possess. 



It has also been commonly affirmed that the reflex power 

 diminishes with age, being the greatest in young animals. This 

 statement, also, has been based on a too limited induction. In 

 Reptiles and Fishes no difference can be detected in this parti- 

 cular. In Birds it is decidedly the other way, the reflex power 

 being much the strongest in adults. Among Mammals the dif- 

 ference is usually in favor of the young animal ; not, however, 

 at the very earliest part of its life, but ten or twelve days after 

 birth. As to man the reflex power appears to be greater in him 

 than in Fishes and Mammals ; but it is not so energetic as in 

 Birds and in Amphibia. 



I have found that the causes of the differences between differ- 



* See rny Inaugural Dissertation, Paris, 3 Janvier 1846, l ere partie. 

 Comptes rendus de 1'Acad. des Sciences, 1847, t. xxiv. pp. 363 et 859. Gaz. 

 Med. de Paris, 1849, t. iv. pp. 430 et 644 ; et 1850 t. v. pp, 98 et 476. 



1* 



