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Show 786 MR. SCLATER ON THE AUSTRALIAN LUNG-FISH. [Nov. 17 young born in 1895-96 was a persistent droop of the evelid observable. " In April 1896 I took twelve of the young and divided the cervical sympathetic nerve in these, and in all on the left side. "The droop of the eyelid was thus again experimentally established in these twelve, and they were allowed to interbreed. "In their young, born in the summer and autumn of 1896, no persistent droop of the left eyelid has been observable. < " M y original stock of six Guinea-pigs has multiplied to over sixty, and the experiment has proved absolutely negative. " I a m able to exhibit to the Society one member of the original stock, two members of the first generation, and four members of the second generation. In the first three the droop of the eyelid experimentally induced is perfectly obvious, and in the last four no such droop is apparent. It remains for m e to suggest a possible source of error in Brown-Sequard's observations. " Just a day or two before Dr. Romanes's death two Guinea-pigs were born, in both of which a partial closure of the left eye was observable, that is to say on the same side as the lesion in the parents. Unfortunately these Guinea-pigs lived only a few days. This case I briefly reported in the columns of ' Nature ' after the death of Dr. Romanes. "Since then I have seen many young Guinea-pigs which have exhibited a partial closure of the eye for some time after birth. This phenomenon is entirely due to conjunctivitis, and is in no sense hereditary; for the right eye and the left eye are equally often affected. The conjunctivitis occurs when the weather is hottest, and m ay be so severe as to lead to the destruction of the eye. In cold weather the conjunctivitis and the droop of the eyelid are absent. The droop of the eyelid disappears when the conjunctiAdtis terminates, and is not therefore persistent. Lastly, I have actually observed the birth of the young guinea-pigs. " O n birth no inequality of the eyes is observable. After birth the new-born he on the ground, and while the parent licks off the membranes, dirt collects into the eyes from the floor of the cage, and thus the conjunctivitis is established." Mr. Sclater exhibited (on behalf of the Hon. H . S. Littleton) a coloured life-sized model of the Australian Lung-fish (Ceratodus forsteri), prepared by M r . A. Alder, taxidermist, of Brisbane; and read a letter from Mr. D. O'Connor, of Oxley, Brisbane, offering to supply living specimens of this Fish. |