206 



the upper part, which has the characteristic appearance of a ganglion, 

 with the olfactory organ. 



From the cells of the ganglion a lot of nerve-fibres are seen 

 emerging and running along the sides of the olfactory lobe, inter- 

 secting its cells. 



The histological appearance of the organ itself is now that of 

 an olfactory membrane, with the characteristic elongated cells. 



.; ^^-m^^jß^^^- 



I J 



Fig. 6. Long. sec. through 01. O. of Torpedo ocellata. Stage 0,-P. 120/1. 



As I have no embryos of a later stage available, I have been 

 unable for the present to follow the process of development further, 

 which, as far as I have followed it, will be found very similar to that 

 in the Teleostei, which I have already examined and described (6). 



Stockholm, Aug. 20^'' 1894. 



Postscript. During the publication of these notes I have 

 become acquainted with C. K. Hoffmann's work : "Zur Entwickelungs- 

 gsschichte des Selachierkopfes" in Anat. Anz., Bd. IX, No. 21, as well 

 as Van Wijhe's communication: "Ueber die Mesodermsegmente und 

 die EntWickelung des Selachierkopfes" in Verhandl. koninkl. Akademie 

 van Wetenschappen te Amsterdam, D. XXII, 1893, and regret that I 

 was unable to notice these works in above notes. • 



