Sept. 28, 1S8S.] 



SCIENTIFIC NEWS. 



339 



Natural ^igtovg* 



THE PROTOPTERI AT THE MUSEUM OF 

 NATURAL HISTORY, PARIS. 

 Thanks to the efforts of Professor Heckel, of the Faculty 

 of Sciences at Marseilles (who must not be confounded 

 with Professor Haeckel of Jena), the menagerie of the Mu- 

 seum of Natural History has just received a most curious 

 fish, the Protoplcnts anncctens (Owen), a creature the 

 singularity of whose habits and the ambiguity of whose 

 organisation have attracted the attention of zoologists for 

 more than half a century. 



The aspect of these worm-like creatures'reminds us, to 

 a certain extent, of that of an eel. They are covered with 

 very distinct scales, and instead of symmetrical limbs 

 they possess merely a sort of filaments fringed upon one 

 of their margins. Of these filaments they make use 

 rather awkwardly, sometimes when they float in the 

 water letting them droop on each side of the body and 

 sometimes giving them an undulatory motion apparently 

 at hazard. According to our present knowledge there 

 exists one only species of this genus, but it is widely 

 distributed throughout tropical Africa from the Senegal 

 to the coast of Mozambique and from the Upper Nile to 

 the Ogoone. Those in the Museum are from the 

 Gambia. 



The habits of this fish have not yet been studied in 

 full detail, though what we know is sufficient to excite 

 curiosity. They inhabit the margins of great rivers, and 

 especially the marshes formed by the periodical inun- 

 dations in the rainy season. At this time the Protopteri 

 lead an active life, swimming along the muddy 

 bottom and feeding on small aquatic animals, or biting 

 off, with their strong and scissors-like jaws, pieces of flesh 

 fromlarger prey which they may seize. Butthe conditions 

 of existence are soon greatly modified. The dry season 

 sets in and the heat of the sun dries up the marshes. 

 The animal knows very well how to accommodate itself 

 to the novel situation. Knowing that the water will 

 soon be deficient it excavates in the mud a cylindrical 

 hole of a depth proportionate to its size, so that when 

 coiled up laterally and the tail placed over its snout the 

 latter may still be. from ten to twenty centimetres from 

 the entrance of the hole (fig. 1). There appears at 

 the same time over the surface of its body a mucous 

 exudation which hardens and forms a solid case, not 

 easily penetrable in fact, a true cocoon. In this the 

 Protoplcnts patiently awaits the return of better days. 



The arrangement of the cocoon seems to in- 

 dicate that it does not result from a simple cutaneous 

 secretion, in which case it ought to produce a covering, 

 having more or less exactly the regularly ovoid, elongated 

 form taken by the fish. On the contrary, it represents a 

 kind of bottle with a hemispherical end below, whilst 

 the opposite extremity, turned towards the mouth of 

 the hole, is covered with a circular lid, marked of from 

 the rest of the cocoon by a very well-defined line of 

 junction. This structure may perhaps be explained 

 by a direct action of the fish, which elaborates its 

 covering intentionally in a definite form, analogous to 

 the procedure of certain insects. Still, it seems more 

 probable that the result is purely mechanical. The 

 mucous secretion forms at first a homogeneous case which 

 adheres strongly to the mud wherever it comes in direct 

 contact. Still, the upper extremity remains free. We 

 comprehend that at the moment of desiccation the sides 



and the bottom will be kept in their place by this 

 natural adherence whilst the free part will stretch, as 

 does parchment if applied whilst moist to the mouth of 

 a vessel, and will finally form a flat portion as if super- 

 added to the case. 



The Protopterus when once enclosed may remain dry 

 for a longer or shorter time in a sort of lethargic sleep, 

 comparable to hybernation, until it is set at liberty by 

 the return of the rainy season. It is then very easy 



Protopteri (Drawn from Nature). 



by digging up, in the dried marshes, the lumps of clay 

 containing these cocoons to transport them without 

 trouble and without any injury to the animal. Those 

 which are now to be seen at the museum, after re- 

 maining six months at the Isle MacCarthy, have still 

 remained dormant for five weeks on their journey to 

 Marseilles and Paris. 



This property, singular for a fish, of being able to 

 pass so long a time away from its normal element, was, 

 we might say, explicable even before we knew its ab- 

 normal habits. - The first type known of the group is the 



