AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, DECEMBER 23 
| 
THE ULTIMOBRANCHIAL BODIES IN POSTNATAL 
PIGS (SUS SCROFA) 
J. A. BADERTSCHER 
From the Department of Anatomy, Indiana University, Bloomington, Indiana 
FOUR FIGURES 
In a recent study (’18) of the ultimobranchial bodies in a wide 
range of successively older developmental stages of pig embryos 
(before their fusion with the median thyroid anlage to full 
term), the writer was convinced that these bodies contribute to 
the structural elements of the thyroid gland. The time at 
which they are completely transformed into typical thyroid 
structures, that is, when they can no longer be recognized 
structurally from the median thyroid anlage, varies greatly. 
Even in a full-term embryo a portion of the ultimobranchial 
bodies may be free from colloid. It thus became evident that in 
order to follow out a more complete developmental history of these 
structures, the thyroid gland of postnatal pigs must be examined. 
The material used for this investigation was obtained from a 
litter of pigs and from three young adult hogs (age unknown). 
The pigs were killed at the following ages: one a few hours 
after birth, one 7.5 days old, one 15 days old, one 28 days old, 
one 42 days old, and one 56 days old. The thyroid and a portion 
of the trachea were removed from the pigs, while only the thyroid 
was removed from the adults. All the material was fixed in 
Zenker’s fluid and imbedded in paraffin. The thyroid glands of 
the pigs were cut transversely into sections 15y in thickness, all 
the sections were mounted in serial order, and stained with 
eosin and Unna’s alkaline methylene-blue solution. The thyroid 
gland of the adults were cut transversely into sections 20y 
thick, only every fifth section was mounted, and stained with 
hematoxylin and eosin. 
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