6 INEZ L. WH1PPLE. 



which the skin is thickly studded, the glandular portions are 

 readily distinguished by the smaller size of the naso-labial 

 glands and of their lumina, as well as by their deeper situation. 

 The acinous glands are a part of the skin and lie within it ; the 

 naso-labial lie beneath the skin. 



In working out the course of the glands two methods were 

 used. The more reliable one as to exact relationships was the 

 serial-section method by means of which the complete course of 

 each tubule may be worked out. Several series both horizontal 

 and transverse were used in this way. The disadvantage of this 

 method lies in the fact that since the glands are of small diameter, 

 much convoluted, and in some regions closely packed together, 

 it is necessary, in order to obtain reliable results, to have thin 

 sections and an absolutely uninterrupted series, conditions which 

 are not easily fulfilled in sectioning an entire head. Even with a 



FlG. 5. Dissection of individual shown in Fig. i, in which the skin is removed 

 from the right side of the head, the naso-labial glands being removed with it. 

 Drawing shows under surface of skin with glands in place, cj, conjunctiva ; /, labial 

 glands; 3-5 and 8-1 1 indicate the enumeration of the naso-labial glands; nli/i, cut 

 end of tubule which lies in the groove of the maxillary bone. Other designations as 

 in previous figures. 



perfect series, moreover, it is extremely laborious to trace even a 

 single tubule throughout its tortuous course. Gross dissections 

 were, therefore, found to be of great value as a means of corrob- 



