6 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." 



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. Proj^erly speaking, birds 

 cannot be said to cry ; their features are immobile, and 

 cannot wear an expression of gi-ief ; 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 or 

 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 a 

 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 diflerent things from tears regarded 

 abstractly as to their aesthetic relations ; at any rate, they 

 subserve a much more useful and sensible purpose. The 

 "lachrymal duct," which is neither more or less than a 

 drainage-tube for the eye, to carry off superabundant tears, 

 or tears that have fulfilled their function and are worn out, 

 commences by two little openings in the anterior lower cor- 

 ner of the eye, and runs into the nose, which is thus made 

 a cesspool to receive the refuse waters of the eye. There 

 is, beside the two above-mentioned, a third gland about the 

 eye, very large and conspicuous in some birds, as the loons, 

 albatrosses, and other swimmers, in which it is lodged in a 



