THE THYREOID GLAND OF THE TELEOSTS 



J. F. GUDERNATSCH 



From the Department of Embryology and Experimental Morphology, 

 Cornell University Medical School, New York City 



TWENTY- ONE TEXT FIGURES AND FIVE PLATES 



During the summer of 1909 at the suggestion of Dr. C. R. Stock- 

 ard^ I undertook the study of the distribution of thyreoid 

 tissue within the gill region of Teleosts, especially of the trout. 

 It seemed important to clear up certain doubtful facts in this 

 connection, since this organ of the trout is liable to disease and at 

 present is attracting considerable attention in cancer research. 

 The examination of but a small number of species brought such an 

 abundance of interesting material to light that I determined to 

 carry out a comparative study of the anatomy and histology of 

 the thyreoid gland in a large number of Teleosts, and to summarize 

 our entire knowledge of the organ in this group of vertebrates. 

 At the same time I attempted, by comparing the present results 

 with the facts known of the thyreoid in other classes, to define 

 more clearly the features of this organ in the entire vertebrate 

 group. 



It gives me pleasure to express my best thanks to The Wistar 

 Institute of Anatomy and to Prof. F. R. Lillie for the use of a 

 room in the Marine Biological Laboratory at Woods Hole, Mass. 

 Some of the species were obtained from the New York Aquarium, 

 for which I wish to thank the Director, Mr. C. H. Townsend. 



Twenty families of Teleosts including twenty-nine species were 

 investigated, the detailed description of which I give in the special 



' My thanks are due to Professor Stockard for many suggestions during the 

 work and for carefully revising this paper. 



journal of morphology, vol. 21, no. 4 

 supplement: februahy, 1911 



