428 PROCEEDINGS OF THE ACADEMY OP [1879. 



December 2. 

 The President, Dr. Ruschenberger, in the chair. 

 Thirty-six persons present. 



December 9. 



The President, Dr. Ruschenberger, in the chair. 



Fifty persons present. 



A paper entitled "Description of a Foetal Walrus," by Harri- 

 son Allen, M.D., was presented for publication. 



Complete Connection of the Fissura Centralis (Fiss. of Ro- 

 lando) with the Fossa Sylvii. Dr. A. J. Parker stated that Dr. 

 Chas. K. Mills had lately observed, while examining the brain of 

 a white person, that the central fissure ran complete^ into the 

 fossa Sylvii without any bridging convolution being found present. 

 The fissura centralis, as it exists in the higher primates, begins at 

 the upper border of the hemisphere, and extends obliquely down- 

 wards and forwards, terminating above the Sylvian, so that we 

 find an arched convolution surrounding its lower end and com- 

 pletely separating it from the Sylvian fissure. In 18(56, however, 

 Turner reported a case (Edinburgh Medical Journal, 1866) in which 

 he found this fissure joining the Sylvian. This appears to be, up 

 to that time, the only recorded case. Ecker, in speaking of this 

 observation (Cerebral Convolutions of Man, trans, by R. T. Edes, 

 M.D., 18*73), says : "I have not yet seen a complete opening of 

 the central furrow into the fissura Sylvii of which Turner speaks;" 

 and Bischoff goes so far as to affirm (Die Grrosshirnwindungen des 

 Menschen, etc., Abhand. der k. bair. Akad. der Wissenschaften 

 Miinchen, 1868), that the central fissure bends with its upper end 

 gradually backwards, but it remains closed at its upper and lower 

 end, and never opens into the fossa Sylvii. In the Proc. of Acad- 

 emy of Nat. Sciences Phila., 1878, Dr. Parker has reported a case 

 similar to those observed by Prof. Turner and Dr. Mills, a photo- 

 graph of which was exhibited ; so that we have now at least three 

 well-authenticated cases in which this relation of the two fissures 

 referred to above existed. Bischoff objects to the observation of 

 Turner on account of its disagreement with certain views in re- 

 gard to the morphology of the cerebral convolutions which he ad- 

 vances in the paper referred to above. He considers that "a large 

 number of the convolutions of the great hemisphere are arranged 

 around the ends of the primary furrows in more or less simple or 



