INTEGUMENT OF NECTURUS MACULOSUS 535 
series (Ciaccio, ’67; Szezesney, ’67; Eberth, ’69; Engelmann, ’72; 
Drasch, ’89; Schultz, 89; Grénberg und Klinckowstrém, ’94; 
Junius, 96; Weiss, 99; Gaupp, 04; Bruno, ’04; Nordenskidld, 
705; Arnold, ’05). On the other hand, several others deny the 
presence of muscles on glands which are mucous in nature (Stieda, 
65; Coghill, ’99; Ancel, ’02; Esterly, ’04; Reese, ’05; Phisalix, ’10). 
In Necturus there certainly are no muscles on the mucous 
glands. In perpendicular sections which are tangential to the 
surface of the sacs of mature glands, no longitudinally arranged 
cells can be found, and, furthermore, in sections cut parallel 
with the body surface no evidence of the existence of a muscular 
layer is obtained. If muscle fibers were present they would 
surely be demonstrated in the latter sections, since in these they 
would be seen in cross-section. 
f) Epithelium and secretion of granular glands. A syncytial 
condition of the secreting epithelium has been described in many 
other Amphibia (Leydig, ’76 a; Drasch, ’94; Seeck, ’91; Esterly, 
04; Reese, ’05; Arnold, ’05; Nordenskiéld, ’05; Nirenstein, ’07; 
Muhse, ’09; Shipley and Wislocki, 715). According to Heiden- 
hain (93 a) and Nicoglu (’93), in Triton the poison cells are 
sharply limited on all sides. They, however, describe ‘tiberreife’ 
conditions in which the cell limits are broken down and the 
granular secretion lies free in the lumen. Leydig (67), Engel- 
mann (’72), Seeck (91; Rana, Triton, Salamandra), and Weiss 
(99) find that the cell walls are obliterated only toward the 
center of the gland, while nearer the gland wall the cells are 
distinctly separated. Schultz (89; Salamandra) and Junius 
(96; Rana) describe a discontinuous epithelium for many granu- 
lar glands. 
In Necturus, within the muscular layer of the mature granular 
glands, are the remnants of the cells which once formed the 
secreting epithelium (figs. 6, 12). All traces of cell boundaries 
are gone and only naked nuclei are left lying at the periphery of 
the gland imbedded in the granular secretion., The nuclei are 
not evenly distributed. Over small areas they may be closely 
associated, in other places they may be entirely absent. Occa- 
sionally nuclei occur in the center of the gland sac, but they 
