-38- 



Is a small group of follicles lined with columnar or cuboldal 

 epithelium (Fig, 10 b). It is surrounded by connective tissue 

 and lies between the tongue muscle above and the median ventral 

 cartilaginous bar below, with a large blood vessel on either 

 side. It extends, as uliiller says, from the 2nd to the 4th gill 

 pouch. The follicles are genera.lly filled with a secretion 

 (not shown in the figures) send, with tii©ir surrounding cells, 

 forn^ in cross section, an oval mass. Usually from four to six 

 follicles are cut in each transverse section. 



Born was the first to describe correctly the salivary 

 or basilar gland in the lamprey, Rathke having mistaken the 

 basilar muscle, in which the gland lies imbedded, for the tissue 

 of the gland, considering the true gland es merely the cavity . 



The gland is paired, and each half lies, as has just 

 been said, imbedded in the tissue of the oorreepondlng half of 

 the large, paired basilar muscle. This muscle lies in the floor 

 of the mouth and pharynx and is one of the muscles used by the 

 animal in adhering to rocks or fish. By oontraotlon of this mus- 

 cle the salivary gland is compressed and its secretion thus 

 forced out. 



In the large adult sea lamprey the two parts of the 

 basilar gland are easily discovered by dissection, lying in the 

 medial sides of their corresponding halves of the basilar muscle. 

 In the much smaller brook lamprey, the position and structure of 

 the basilar gland may be made out by stained serial sections 



