16 
Casey A. Wood. 
the secreted product is viscid. This gland is larger than the lach- 
rymal gland, and belongs to the tubular-alveolar type. 
According to Sardemann (Beitrdge zur Anatomie der Tranen - 
druse, Inaug. Diss., Freiburg, 1887), the lachrymal gland in Birds 
lies in the outer angle of the eye about the equator of the globe. 
Its size depends more than anything else upon the size of the ani- 
mal. It has a thin capsule and is of lobular structure. Inside each 
lobule one finds a collecting space connected with tubular ducts 
lined by cylindrical cells with round or flat nuclei. There is no 
true lachrymal sac. 
In the Hen the lower canaliculus is the smaller of the two canals 
and is slightly and almost immediately in front of the anterior 
canthus. Its flattened opening, continuous with the peripalpebral 
Fig. 10 — Side View of the English Sparrow with the External Walls of 
the Lachrymal Canals, ic, Removed, x 4. (Wood and Slonaker.) 
groove, is about 2 mm. wide. The upper canaliculus, separated 
from its fellow by a narrow bridge of tissue, has an opening about 
twice the size of the inferior entrance. It lies appreciably above 
and still farther toward the front of the beak than the lower open- 
ing. 
A thin partition of soft tissue divides the two canals for a dis- 
tance of 3 mm., when they join to form the lachrymal duct, whose 
calibre is equal to that of the combined upper and lower canaliculi. 
As in the Sparrow, the Hen has no well-defined lachrymal sac (as 
in Man), nor are there true puncta supplied with a suction appar- 
atus, the openings into the tear canals being evidently mere drain- 
age vents. On the other hand, the communication with the buccal 
cavity is large and unobstructed, so that the tears are readily swept 
into the throat with every excursion of the nictitating membrane 
and of the true lids. 
