NASO-LABIAL GROOVE OF LUNGLESS SALAMANDERS. 7 



oration of results obtained from the study of serial sections. It 

 was found possible, with alcoholic specimens, to dissect off the skin 

 from the entire head, removing with it all of the soft parts, eye- 

 balls included, external to the skull ; and such dissections, while 

 always involving more or less injury to some of the tubules, were 

 still sufficiently good so that, when the skin was pinned out under 

 water and further dissection and separation of the glands accom- 

 plished, practically every anatomical fact which had been learned 

 from the sections could be demonstrated. 



The naso-labial glands are tubular glands much convoluted, 

 and showing a tendency to develop acini at the bends of the 

 tubules. The different glands of the group show great inequality 

 both in complexity and in length of the tubules. The longest 

 and most complicated are the two which are associated with the 

 naris itself [referred to as (;//,) and (;//,) in the figures] . Both of 

 these are not only much convoluted but are branching. The 

 dorsal gland (;//,) often sends several branches as far posteriorly 

 as the orbit, over the edge of which a few tubules usually find 

 their way, while some may even extend entirely across the inner 

 surface of the eyeball. The duct of the second gland (/// 2 ) ex- 

 tends ventrally for a little distance beneath the groove, and then 

 gives off almost at right angles several branches both mesial and 

 lateral. The lateral have been in some specimens traced in a 

 course parallel with the edge of the lip as far posteriorly as the 

 eyeball, while the mesial extend nearly to the mid-line and then 

 may turn in a dorsal direction. 



Of the remaining naso-labial glands (Fig. 5, J-J, <?//), some 

 are several millimeters in length, others much shorter. All, 

 however, are long enough to be classified as tubular glands. 

 The shorter glands are in general those opening along the more 

 ventral portion of the groove, and along the horizontal groove 

 (gi'l} only very short ones have been observed. All of the 

 longer tubules lie beneath the skin parallel with the edge of the 

 lip, extending either mesially or laterally from the groove, and 

 they sometimes equal in length the single branches of the large 

 gland (/,) which opens on the ventral border of the naris. Occa- 

 sionally a mesial and a lateral tubule unite and open by a single 

 duct (Fig. 4, dnl}, thus forming a branching gland. 



