THE ENDOCRINE SYSTEM OF TYPHLOMOLGE 



RA TUB UNI. 



EDUARD UHLENHUTH, Pn.D. 



(From the Laboratories of The Rockefeller Institute for Medical Research, New 



York, N. Y.) 



The endocrine system of Typhlomolge rathbinri, the blind Texan 

 cave salamander, has been a matter of controversy for some time. 

 In order to clarify some of the points under discussion, I have 

 made serial sections of the region of the lower jaw, throat, and 

 heart of 5 specimens, and the entire head of 2 specimens of this 

 animal. The specimens were captured in Texas, as described in a 

 previous article. 1 Six of them died during the trip from Texas to 

 New York, one after 14 months of captivity in the laboratory. 

 Since they are preserved after death, only the anatomical features 

 of the various organs can be studied. A histological study must be 

 postponed until suitable material can be secured. 



THE THYROID. 



Emerson 2 was the first one to call attention to the possible 

 absence of the thyroid gland in Typhlomolge. In 1905 she ex- 

 amined sections through the head of one specimen and was una- 

 ble to find a thyroid. At the time Emerson published her paper 

 the interest in the endocMne system of amphibians was very slight 

 and her paper remained unknown to most biologists. In several 

 of my papers on the thyroid function of salamanders I have called 

 attention to Miss Emerson's interesting findings, which I had 

 recognized to be correct. Soon after my return from Texas in 

 1916, I sectioned one of the Typhlomolge captured there and 

 found the thyroid absent. 



But at the 1921 Christmas meeting of the Anatomists, Swingle, 

 apparently unacquainted with the literature on these facts spoke 

 of the thyroid of Typhlomolge as a matter of fact and claimed 

 to have isolated and observed this organ under the microscope. 



1 Uhlenhuth, E., Biol. Bull., 1921. XL., 73. 



2 Emerson, E. T., Proc. Soc. Nat. History, Boston, 1905, XXXII., 43. 



303 



