778 



J. F. GUDERNATSCH 



Fig. 20. Sections through the thyreoid gland of Muraenoides. A, anterior to 

 the aortic bifurcation; B, between the first and second; C, close to the second 

 branchial arteries. 



scattered follicles. In the middle portion of the gland the folli- 

 cles are numerous and closely arranged. At the aortic bifurcation 

 they lie around a large vein and completely fill out the space 

 between the gill arch and muscles. The lateral extension of the 

 follicles is small as compared with the dorso-ventral, since the 

 isthmus is narrow (fig. 20, B). A cross section through the thy- 

 reoid area measures about 1 mm. Taking 1 mm. as the average 

 width we would have 10 cubic mm. of thyreoid tissue in this speciee. 



