Literary Notices. xHx 



occupying a lateral position with respect to the central canal. One of 

 the main processes (Studnicka calls them both axis cylinders) passes in 

 a longitudinal direction, while the other emerges with the dorsal root. 

 If this identification be correct Reissner's cells occur throughout hfe in 

 Amphioxus, Petromyzon, Protopterus, Triton, and certain teleosts, 

 while in the selachians and ganoids, as well as some others, they are 

 embryonic and transient. 



In Lophius it will be remembered that they have a very restricted 

 but speciahzed occurrence. The form is generally crescentic with the 

 concavity mesal. One of the processes crosses to the opposite side of 

 the cord and passes either toward or from the head. The other or 

 true axis cylinder originally passed directly ectad and innervates the 

 myotome, though in some cases it associated itself with the dorsal 

 root. Burckhardt's " Randzellen " described in Protopterus are found 

 to occur in Petromyzon also, but they have nothing to do with the 

 Reissner's cells. The term selected by Studnicka, " Hinterzellen," 

 suffers from ambiguity common to the German terms of direction. If 

 we substitute " dorsal cells " there is a possibility of confusion with 

 cells of the dorsal cord so that the familiar term Reissner's cells may 

 still be employed. 



In a second paper' the same author describes the expansion of the 

 canalis centralis found at the caudal extremity of the cord of Amphi- 

 oxus and the Cyclostomata and differentiates it under the name " Sinus 

 terminalis" from the " Sinus sacralis " of acaudal vertebrates. Such 

 significance as this ventricle has may be assumed to be in connection 

 with the equilibrium of the cerebro-spinal fluid. 



c. L. H. 



Anatomy of the Cerebrum of Notoryctes. ^ 



Although based on imperfect material and studied under adverse 

 conditions, the notes upon the brain of this litde-known marsupial will 

 prove welcome. In respect to the brain at large the small size of the 

 cerebrum and limited extent of pallium are correlated with the exposure 

 of a relatively large part of the corpora quadrigemina and a very sim- 

 ple condition of the cerebellum. 



The cerebrum presents an extreme simplicity of structure and 

 while is has superficial resemblances to Talpa and Dasypus it is yet in 



'Ueber die terminale Partie des Riickenmarkes. 



2G. Elliot-Smith. The Comparative Anatomy of the Cerebrum of No- 

 toryctes typhlops. Trans. Roy. Soc. Australia, 1895. 



