TIIYRSOPTERIS. 



[ 7G6 ] 



THYROID GLAND. 



Avith simple, swolJeu, traversing canala, and 

 fa.<cicules of smaller tubes (2 species, Ter- 

 tiary ) : 4. Gi/roporeUa ; cylindrical, with 

 circular canals (14 species, Triassic and 

 Neocomian) : 5. Uteria ; annular, hollow, 

 perforate (1 species. Tertiary). 



BiBL. Giimbel, Abhandl. k. hayer. AJcad. 

 Wiss. 11. a. xi. 1872, p. 231. 



THYRSOP'TERIS, Kunze.— A genus of 

 Cyathese (Polypodiaceous Ferns), with glo- 

 bose, marginal sori, collected into a panicle 



Fig. 745. 



Fig. 741. 



Fig. 742. 



Thyrsoi^teris olegans. 



Fig. 741. A fertile pinna. 



Fig. 742. A pinnule converted into a cup-like Poru3. 

 Magnified 20 diameters. 



distinct from the sterile pinnfe. Capsules 

 sessile, on a globose receptacle ; indusium 

 inferior, cup-shaped, the mouth entire. T. 

 eleijans, tropical. (Hooker, Si/71. 15.) 



Fie. 743. 



Fig. 744. 



Thyrsopleris elegnns. 

 Fig. 743. Yertieal section of the same, with the spo- 

 ranges removed from the columella. 



Fig. 744. Side view of a sporange. Magn. 100 diams. 



TH Y^'ROID GLAND.— The thyroid gland 

 is one of the vascular gland.-*, or glands with- 

 out ducts. 



It consists of rounded, closed, glandular 

 vesicles (tig. 745) surrounded by or imbedded 

 in a fibrous stroma (a), and aggregated into 

 rouiidi.sh, elongate, or somewhat polygonal 

 acini or minute lobules, these being grouped 

 in secondary lobules, which unite to form 





Glandular vesicles from the thyroid gland of a child. 

 a, intervening c onnective tisbue ; b, basement mem- 

 brane ; c, epithelium. 



Magnified 250 diameters. 



lobes. The vesicles are from 1-600 to 1-240" 

 in diameter, the acini from 1-50 to 1-24' '. 

 The Strom a is condensed around the lobules, 

 to form a fibrous coat. 



The stroma consists of ordinary interlacing 

 bundles of connective tissue, with fine elas- 

 tic fibres, at its outer surface containing fat- 

 cells. 



Fiff. 746, 



Glandular vesicles with- colloid matter 

 Magnified 50 diameters. 



The vesicles consist of a basement mem- 



