Literary Notices. xxiii 



6. The nerve cells possess higher nervous functions as well as 

 nutritive processes. 



7. The nerves are not to be regarded as completely isolated in- 

 dividuals (in the sense of Waldeyer's neuromes.) 



The figures accompanying the paper are excellent and seem to 

 establish his positions. It may be remembered that Herrick has de- 

 scribed the connection of the nerve cells in the retina by a reticulum. 

 (See Festschrift for Leuckart.) 



The Yital Node. 



Gad and Marmescoy, according to Brown-Sequard, have been 

 studying the respiratory centre and have shown that the spot which it 

 has been customary since Flourens to speak of as the vital node may 

 be removed without destroying the respiratory rhythm. There is, 

 however, a mass of cells lower in the medulla which has the respira- 

 tory function. There has been something improbable in the state- 

 ments given in our text books and we are prepared to find that the 

 relations are less simple than we have been told. 



Studies upon the Head of Craniate Vertebrates.^ 



The first number of this most valuable monograph is chiefly de- 

 voted to the development of the head of Acipenser sturio. We re- 

 serve an account of the details for another occasion and glance simply 

 at some of the theoretical conclusions which make up a large part of 

 the work. 



One important result has been the discovery of a dorsal neuro- 

 pore situated in a thickened epidermal plate. This pore is obviously 

 the homologue of the similar organ found in the larval amphioxus. The 

 projection resulting from the separation of the brain from the epider- 

 mis, i. e. due to the separation at the neuropore, constitutes the lobus 

 olfactorious impar, and this represents permanently the very front of 

 the brain. [The dorsal front, it would seem, for the origin of the 

 pore is obviously from the dorsal aspect of the tube.] The author 

 finds himself in agreement with Van Wijhe who found the point of 

 connection of skin and brain in the bird embryo between the epi- 

 dermal thickenings or fundaments of the olfactory. Kupffer, how- 

 ever, finds in Acipenser a median olfactory plate. He considers it 



^C. VON Kupffer. Studien zur Vergleichenden Entwicklungsgeschicte 

 des Kopfes der Kranioten, Munich and Leipzig. J. F. Lehmann. 1893. 

 Price 10 marks. 



