91 
Nachdruck verboten. 
The Development of the Thyroid Gland in Bdellostoma 
STOUTI. 
By Cuarues R. STOCKARD. 
With 8 Textfigures. 
In two recent numbers of this Journal articles have appeared in 
which the adult conditions of the thyroid gland in Myxine were con- 
sidered. The first of these was by F. J. Corz!) in which the author 
refers briefly to the thyroid as consisting of alveoli diffusely scattered 
below the pharynx in the gill region, and compares this condition with 
that in the bony-fish, a comparison earlier made by Maurer?) The 
second and more extensive article by ScHAFFER®) calls attention to the 
remark made by Core that the thyroid in Myxinoids had not been 
previously recorded and cites among other references the early descrip- 
tion of this organ by WırneLm Mürtert) and subsequent references in 
the work of Maurer?) and GEGENBAUR). 
ScHAFFER then gives a very clear and interesting account of the 
structure of the thyroid in the adult Myxine, finding the gland to con- 
sist of alveoli diffusely scattered throughout the gill region below the 
pharynx and dorsal to the branchial aorta. This region of the body 
is filled with large fat cells and in this fat mass the thyroid alveoli 
are loosely scattered. The histology of these alveoli was very carefully 
described, and so far as I have found agrees rather closely with the 
structures in Bdellostoma. Scuarrer concludes his paper with the fol- 
lowing very just and pertinent statement. 
„Was nun die Deutung dieser verstreuten, interbranchialen Drüsen- 
blasen anlangt, so wird eine solche so lange unmöglich sein, als man 
die Entwickelung der Blasen nicht kennt. Immerhin mögen einige Ge- 
sichtspunkte, welche auch dann für diese Deutung maßgebend sein 
müssen, jetzt schon besonders hervorgehoben werden.“ 
1) Notes on Myxine. Anat. Anz., Bd. 27, 1905, p. 324. 
2) Schilddrüse und Thymus der Teleostier. Morph. Jahrb., Bd. 11, 
SSb ep. 129.07 ° 
3) Berichtigung, die Schilddrüse von Myxine betreffend. Anat. Anz., 
Bd. (28, .1906, p. 65. - 
4) Beobachtungen des pathologischen Institutes zu Jena. 4. Ueber 
die Entwickelung der Schilddrüse. Jenaische Zeitschr., Bd. 6, 1871, 
p. 428. 
5) Vergl. Anatomie der Wirbeltiere, Bd. 2, Leipzig 1901, p. 251. 
