
510 BIRD’S-EYE VIEWS. 
When these vessels become engorged with blood, as occurs 
in congestion or inflammation of the conjunctiva, they are 
very distinctly seen, and we have the state of things that is 
called “blood-shot.” i 
Before examining the eyeball, which at length we have 
reached, let us glance at some accessory structures that are 
found lying with it in the socket. Properly speaking, birds 
cannot be said to cry; their features are immobile, and 
cannot wear an expression of grief; but they can shed 
tears. The tears are elaborated by two small glands that 
lie inside the eyelids, one in each corner. These are both 
“lachrymal” glands; but the one that lies in the corner next 
the beak is called the “Harderian gland.” It is smaller than 
the other, nodulated in shape, and deeply seated inside the 
nictitating membrane, upon which it pours out a viscid of 
glairy secretion through a small opening, the mouth of a 
short duct that receives branches from all parts of the gland. 
The nictitating membrane requires constant oiling to work 
easily ; the Harderian gland is an oil-can that can both make 
the oil and apply it when needed. The other, more truly 3 
lachrymal, or “tear” gland, pours its secretion into the pos- 
terior or outer corner of the eye, near the juncture of the 
two outer lids, which are thus kept soft and moist on the 
inside. Tears, in the concrete, viewed anatomically or phys 
iologically, are very different things from tears Ts 
abstractly as to their esthetic relations; at any rate, 
subserve a much more useful and sensible purpose 
“lachrymal duct,” which is neither more 
drainage-tube for the eye, to carry off superabundant i, 
or tears that have fulfilled their function and are wor? 
they 
commences by two little openings in the ant 
ner of the eye, and runs into the nose, whic 
abou 
a cesspool to receive the refuse waters of the eye + the - 
is, beside the two above-mentioned, a third gland 
eye, very large and conspicuous in some birds, as 
albatrosses, and other swimmers, in which it 1 
or less than ® — 





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