492 Wisconsin Academy of Sciences, Arts, and Letters. 
eosin has stained this part. This.might lead one to hold that 
each gland secreted a different fluid, which view would he 
further shown by the presence of the two ducts, even if they did 
join at one point. We were unable to trace either duct further 
than the anterior part of the head and do not know whether they 
empty into the same or different places. From the anterior end 
of each gland (PI. XXXIY, Fig. 7) there arises a duct which is a 
continuation of the longitudinal median tube already mentioned. 
The tube from the large gland, soon after its exit, widens, and 
in this widened part is a mass of cells, the nature of which we 
were unable to determine; it soon narrows again and at this 
point received the duct from the smaller gland. The single 
duct formed by the union is very short and divides to form the 
two long ducts passing forward into the head. 
Locy (5) called attention to the similarity between the ducts 
of the salivary glands and the trachea, a comparison which at 
first is very striking. There is the transverse striation, due ap¬ 
parently to the taenidia winding spirally around the duct and 
having the glistening appearance so characteristic of the trachea. 
A longitudinal section shows, however, that this similarity does 
not remain. There is an internal chitinous layer (PI. XXXIY, 
Fig. 8) quite wide and rigid internally, the alternate thick and 
thin layers giving of course the appearance of the taenidia, but 
yet quite different. Externally there is a thin chitinous layer 
and between the two a single row of flattened cells. 
In the figures given both by Dufour (2) and Locy (5) there 
is seen on either side between the oesophagus and the salivary 
glands a long narrow tube extending for quite a distance back¬ 
wards on the alimentary tract. On these tubes, at a place near 
the posterior end of the salivary glands, there is shown an en¬ 
largement which in the figures of both authors, is very notice¬ 
able. These are figured as the non-glandular portions of the 
salivary glands. In a general dissection these long tube-like 
bodies are seen at either side of the anterior portion of the mid- 
intestine and extend as far as the posterior end of the second 
abdominal segment. (PI. XXXIY, Fig. 1.) They can be traced 
forward at either side of the oesophagus to the thoracic gang¬ 
lion where each bends outward to pass around it. From here 
they run forward a short distance and then pass into a very 
long, thin duct, similar to those of the salivary glands, which 
extends into the head. Xear the thoracic ganglion there is an 
