MANATEE. 20 1 



with (he sou ; and if a Manatee exists there we should have what at first sight would appear to bo 

 a parallel case to the occurrence of the Seal in the Caspian Sea and Lake Baikal. But it would 

 not be so in reality. It is only a repetition of the lesson which we are constantly receiving not 

 to assume that similar results are always produced by the same causes. If it were so, the only 

 means by which the Manatee could be supposed to have reached Lake Tschad would be by a 

 depression of the land suflicient to allow a water communicatiou between it and the sea. Lake 

 Tschad would then be a gidf of the sea ; and if the land rose and converted it into a land-locked 

 lake, the Manatees which happened to be in it would be retained there under new conditions of 

 life. But in Lake Tschad there is no need for such a machinery. The watershed between the Lake 

 and the Sea is not a lofty range of mountains, from one side of whicb the rivers run into Lake 

 Tschad, and from the other into the Niger, but a flat, marshy tract of land, so nearly level, that 

 it is almost an equal chance by which way the waters will run from it. It is like a large peat- 

 bog, or a gigantic sponge, out of one side of which creeps the Arre and Shari, and out of the other 

 the Biuue. The Hippopotamus goes easily from the one to the other, and in the rains, when the 

 coxmtry becomes flooded, the natives go about in boats. It is like an inundation, so that the 

 Manatee coidd with ease come up from the Atlantic, and find its way into Lake Tschad. 



The case, therefore, is anything but parallel with the Caspian and Lake Baikal. But in the 

 great system of lakes, on the other side of the African Continent, there may be an instance bearing 

 more relation to them. 



Dr. Kirk informs me that the natives of the Zambesi district spoke of a large animal, which 

 was not the Hippopotamus, but as large as it, inhabiting Lake Shirwa. Of course, the natives were 

 familiar enough with the Hippopotamus, and not likely to make any mistake as regards it ; but as 

 the animal was not actually seen by any of Dr. Livingstone's party, the statement is only of 

 importance as indicating a point to be inquired into when occasion serves. 



The inquiry is of interest in many ways, from the inferences which may flow from it. The 

 fact of a Sirenian existing there might modify the present views of geologists as to Africa having 

 remained above water since the secondarj^ period ? Its existence there might compel us to admit 

 that a former communication must have subsisted between the lakes and the sea, as there is no other 

 means by which it could have surmounted the Murchison Rapids which lie between them; and 

 to admit of such a communication the land must have been dejDressed to a greater or less extent. 

 To what opposite conclusions might we not be led according as the Sirenian there should prove 

 to be a Manatee or a Dugong — a new species, or one already known ! If the latter, the course of 

 change must have been slow — if the former, it must have been comparatively rapid and sudden. 

 If the creature were a Manatee, it may have found its way from the south ; if a Dugong, it would 

 probably obtain access from the north. 



But we must not allow ourselves to luxuriate in such speculations. The whole of our airy 

 vision depends upon " the vain breath of a Nerjro man." But, nevertheless, the Negro's knowledge of 

 species often beats that of the naturalist, and they are very cunning — in some better things than 

 bodiless creations. 



Two other species of Manatee are found in Atlantic waters, but they are only found on the 

 coasts on the other side; on the shores of America between the Tropics. The fossil one described 

 by Harlan from the western coasts of Maryland, is scarcely accepted by naturalists, more 

 perhaps, from his determination not having been endorsed by any otlier Paliuontologist, 

 than for any other reason. His determination was made from the ribs and vcitcbra', and 



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