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necessity of a totally different mechanical arrangement for the 

 third eye-lid, from that which exists in such a simple form in 

 the horse. 



" In the elephant the gland of Harder is very large, of 

 an oval, flattened form, placed at the inner and anterior part 

 of the orbit, and quite distinct from the surrounding adipose 

 and cellular tissue ; its duct, about an inch and a half long, 

 runs parallel to the pedicle of the cartilage, and opens behind 

 the root of the nictitating membrane by a distinct foramen, large 

 enough to admit a common probe. The caruncula lachry- 

 malis is also large, a proof that this body is not to be re- 

 garded in other animals as the analogue of Harder's gland, 

 but rather as a part of the system of Meibomian or ciliary 

 follicles. The true lachrymal apparatus is absent in the 

 elephant ; a few red granules or mucous glands beneath the 

 conjunctiva in the superior external palpebral sinus alone in- 

 dicate its usual site ; there are no lachrymal puncta, ducts, 

 or sac. The highly developed middle eye-lid, with the Har- 

 derian gland, supply the place of this apparatus. In the 

 horse the lachrymal gland is present, also the puncta, ducts, 

 and sac, but the Harderian gland is rather a follicular series 

 entangled in the fat ball, and opening by several fine ducts on 

 the ocular surface of the nictitating cartilage. In the bird 

 the Harderian gland is very large and distinct, as also the 

 lachrymal, and there is a slit-like passage for the secretions 

 to flow into the nose. 



" It is unnecessary here to allude to the temporal glands, 

 which are peculiar to the elephant, as they have no connex- 

 ion whatever with the palpebral apparatus ; their secretion 

 is probably odoriferous, and, like that of the larmiers or infra- 

 orbital sacs in the antelope species, has some connexion with 

 the sexual functions. 



" There is one peculiar feature in the anatomy of the 

 orbit of the elephant, which I think worthy of demonstrating 

 on the present occasion, though unconnected with the lachry- 



o 2 



