Abstract
WHEN THE normal thyroid of the turtle, Emys europaea, was studied (i) it as found that no substantial histological difference existed between this form and other vertebrates. Innervation of the gland is supplied by the vagus and the sympathetic. Seasonal changes alter the thyroid activity. Species which are relatively active during the winter, such as the English sparrow (2), the albino rat (3) and Anolis carolinensis from the environs of New Orleans (4), seem to have activated thyroids with little colloid storage during the coldest months, while in the spring and early summer such thyroids have low cuboidal epithelial cells and marked colloid storage except during normal ovulation (4). In contrast, animals which hibernate, such as the European species of Lacerta in Germany (5), the ground squirrel, Citellus (6), the bat and hedgehog (7, 8), and frogs (9, 10), show a reversal of this activity, the thyroid being inactive with low cuboidal epithelium and marked colloid storage, while in spring and early sum...
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
