The Development of the Olfactory Organ in the 
Teleostei. 
By 
John. F. Holm. 
(Zootomical Institute University of Stockholm.) 
Mit Tafel XVII und 1 Figur im Text. 
The development of the olfactory organ of these fishes has 
been little studied and we have only one short account of this 
process, which is by C. K. Horrmann in his large work »Zur On- 
togenie der Knochenfische« relating to Salmo. As to other kinds 
of fishes, there are two descriptions by BALFOUR, one in »The 
Development of Elasmobranch Fishes« and the other in »The Strue- 
ture and Development of Lepidosteus« both contained in the Memo- 
rial Edition of his works. 
In spite of careful research, I have been unable to find any 
other literature on the subject. . 
I have now tried to follow the process of the development in 
Salmo salar, as material there-of could easily be had and the 
development is slow. I here take the opportunity to express my 
gratitude to Professor LECHE, who suggested this work to me, as 
well as to thank him for all the kind assistance he has given me 
during the time of execution. For material I applied to Elfkarleö 
Salmon Cultivating Establishment from where I obtained eggs which 
were artificially impregnated ten days before I recieved them and it 
took, on the average, 95 days, in the cold winter temperature, for 
them to hatch. The ova were fixed in KLEINENBERG’s Sulpho- 
Picric acid, then opened and the embryo taken out and stained intoto 
