1832*3.] THE TUCUTUCO. 49 



The man who caught them asserted that very many are inva- 

 riably found blind. A specimen which I preserved in spirits was 

 in this state ; Mr. Eeid considers it to be the effect of inflammation 

 in the nictitating membrane. When the animal was alive I placed 

 my finger within half an inch of its head, and not the slightest 

 notice was taken : it made its way, however, about the room nearly 

 as well as the others. Considering the strictly subterranean habits 

 of the tucutuco, the blindness, though so common, cannot be a very 

 serious evil ; yet it appears strange that any animal should possess 

 an organ frequently subject to be injured. Lamarck would have 

 been delighted with this fact, had he known it, when speculating * 

 (probably with more truth than usual with him) on the gradually 

 acquired blindness of the Aspalax, a Gnawer living under ground, 

 and of the Proteus, a reptile living in dark caverns filled with 

 water; in both of which animals the eye is in an almost rudi- 

 mentary state, and is covered by a tendinous membrane and skin. 

 In the common mole the eye is extraordinarily small but perfect, 

 though many anatomists doubt whether it is connected with the 

 true optic nerve ; its vision must certainly be imperfect, though 

 probably useful to the animal when it leaves its burrow. In the 

 tucutuco, which I believe never comes to the surface of the ground, 

 the eye is rather larger, but often rendered blind and useless, though 

 without apparently causing any inconvenience to the animal ; no 

 doubt Lamarck would have said that the tucutuco is now passing 

 into the state of the Aspalax and Proteus. 



Birds of many kinds are extremely abundant on the undulating 

 grassy plains around Maldonado. There are several species of a 

 family allied in structure and manners to our Starling: one of 

 these (Molothrus niger) is remarkable from its habits. Several 

 may often be seen standing together on the back of a cow or horse ; 

 and while perched on a hedge, pluming themselves in the sun, they 

 sometimes attempt to sing, or rather to hiss; the noise being very 

 peculiar, resembling that of bubbles of air passing rapidly from a 

 small orifice under water, so as to produce an acute sound. Accord- 

 ing to Azara, this bird, like the cuckoo, deposits its eggs in other 

 birds' nests. I was several times told by the country people that 

 there certainly is some bird having this habit ; and my assistant 

 in collecting, who is a very accurate person, found a nest of the 

 sparrow of this country (Zouotrichia matutina), with one egg in it 

 * Philosoph. Zoolog., torn. i. p. 242. 



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