201 



the inner and outer funnels of Acipenser would be found to be in 

 strict correspondence. 



The resemblances between the pronephros of Amia and that of 

 Lepidosteus were to be expected, for, as far as one can judge, there 

 are many close parallelisms in the development of these two forms. 

 In the case of the pronephros in Lepidosteus the organ is less re- 

 duced as to its funnels, and is therefore more primitive than that of 

 Amia, Whether the organ in Acipenser is really the most primitive 

 of the three can hardly yet be determined for the reasons given above, 

 and therefore it is at least premature to set it up as the organ from 

 which, by reductions, the pronephros of Lepidosteus and of Amia may 

 have been derived. However one may be inclined to doubt the cor 

 rectness of some of his conclusions, the merit and excellence of Jun 

 gersen's work must be recognised. 



Nachdruck verboten. 



Some Notes on the early Deyelopment of the Olfactory Organ 



of Torpedo. 



By JoHK F. HoiM. 

 (Communication from the Zootomical Institute, University of Stockholm.) 



With 6 Figures. 



Balfour (1) gives a short description of the early development of 

 the Olfactory Organ of Elasmobranch fishes, but beyond this account 

 I have only found it mentioned by the Ziegler's (2) in their work 

 on the development of Torpedo. 



As these descriptions are very incomplete it was of interest to 

 follow the development closely and I obtained from the Zoological 

 Station at Naples a serie of Torpedo embryos ranging from the 

 stadium F to about P, according to the nomenclature used by Bal- 

 four and ZiEGLER. 



These embryos had been beautifully fixed in Sublimate at Naples. 



I stained the head parts intoto in Alum-Carmine or in Haemato- 

 xylin, embedded them in paraffin and cut series by microtome. In 

 the youngest embryos investigated, corresponding to F by Ziegler, 

 or perhaps nearer a stage between F and (r, no commencement of a 

 thickening of the ectoderm could be found, but in the next stage, or 

 about between G and fl, the first indication there-of is plainly visible. 



