{'fraction_non_alphanumeric': 0.013157894736842105, 'fraction_numerical': 0.008771929824561403, 'mean_word_length': 5.008771929824562, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Embryologic origin of the various epithelial cell types in the second kind of thyroid follicle in the C3H mouse

The thyroid gland of the C3H mouse is composed largely of the usual follicle but it also contains a second kind of follicle. To ascertain the embryologic origin of the cell types in each of these follicles, ventral pharyngeal outpocketings and ultimobranchial outpocketings were isolated (before they fused to form the thyroid gland) from the 12‐day‐old fetus of the C3H mouse. The outpocketings were implanted into different kidney capsules of adult C3H mice and were allowed to grow for several months. Transplants were then excised and examined by electron microscopy.