l62 



NA TURE 



S^June 1 6, 1887 



the lake. Off the station of Mabagi, on the north-west shore 

 of the lake, Dr. Junker found a long, low, sandy island, which 

 he recognized as of quite recent formation ; for in 1879 he 

 noticed that the spot where it now lies was covered with shallow 

 water. Its length is 1067 yards, and maximum breadth 99 yards. 

 Tall grass and weeds grow at the water's edge, and a species of 

 acacia {A. mellifera) on the higher parts. The island, Emin 

 Pasha states, is due to the deposition of the detritus brought 

 down by the two rivers which enter from the south-west. From 

 what he observed on the lake, he is inclined to believe that the 

 foreshore on the west is gradually encroaching on its waters ; in 

 other words, the lake in this part is gradually filling up. As 

 for the lake itself, Emin Pasha attributes its origin solely to 

 erosion. He thinks it more than probable that formerly a large 

 stream may have made its way from between the two ranges to 

 east and west of the lake, so that its erosive action, combined 

 with that of inundations, heavy rains, caving-in, and the in- 

 fluence of the sun and weather, are quite sufficient to account 

 for the result. The geological formation of both ranges is the 

 same ; their altitudes differ but little, and the terrace-like forma- 

 tion of their descent lakewards is in each case exactly alike. 

 Emin Pasha hoped to examine the problem much more minutely. 

 He landed at Kibiro, on the opposite side cf the lake, and gives 

 an interesting description of the valuable salt-mines of the 

 region. Emin Pasha afterwards made two other journeys on 

 the lake, during one of which he discovered what he believes 

 to be a new river, called Kakibbi by the Wasongora, 

 and Dueru by the Wamboga. It flows from the Ussongora 

 Mountains, and is of considerable size, and enters the lake at 

 the south, having a large island near lis embouchure. It abounds 

 with cataracts, and is therefore unnavigable. To the south-west, 

 Emin Pasha was informed, there is a large river on the banks of 

 which there is a colony of Akkas — called Balia by the Wanyoro 

 people, but by themselves Betua ; the latter a name suggesting 

 the Batua recently discovered by Lieut. Wolf on the Sankui'u, to 

 the south of the Congo. Is it not possible that the Kakibbi is 

 the same as the "red river" discovered by Mason Bey in 1877, 

 entering the south extremity of Lake Albert ? 



In the Bulletin of the Lyons Anthropological Society will be 

 found an interesting paper by M. Bertholon on the " Arab 

 Colonization of France," in which the author, mainly on the basis 

 of place-names, seeks to identify the existing effects of the Sara- 

 cenic invasion of France. Dr. Collomb has also a useful paper 

 on the peoples of the Upper Niger, their manners and their 

 history. 



M. Edouard Dupont, Director of the Brussels Natural 

 History Museum, is about to leave for the Congo, to make a 

 geological investigation of the region along the south bank of 

 the river, between Boma and Stanley Pool. He will endeavour 

 especially to determine the epoch when the river broke through 

 the coast range, and the age of these mountains. He will also 

 explore any caves which may exist, in order to discover if there 

 are any remains of a primitive population. 



The new number of Petermann's Mitteihingen is one of 

 special scientific intere-t. The first paper gives the results of a 

 series of researches by Japanese botanists on the botanical zones 

 of Japan, in which the relation of these zones is shown to the 

 configuration of the surface of the country. A much longer and 

 perhaps more important paper in the same department is Herr 

 Ernst Hartert's account of the botanical results of the expedition 

 to the Niger under the late Herr Flegel ; it abounds with 

 detailed information on the plants collected by the expedition. 

 Dr. Alex. Supan, the able editor of the Mitteilungen, who takes 

 a special interest in meteorology, contributes a carefully 

 elaborated paper on the mean duration of the chief heat periods 

 in Europe. Then we have a series of extracts from Emin Pasha's 

 letters, from 1883 down to 1886, much of which has already 

 been published. 



THENEPHRIDIA OF '' LAN ICE CONCHILEGA," 

 MALMGREN> 



CEVERAL accounts of the nephridia of Terebella conchi- 

 •^ lega have been given. H. Milne-Edwards {Ann. d. Sci. 

 Nat. (2) Zoologie, x., 1838, p. 220), in a paper published in 

 1838, on the circulation in Annelids, describes the vascular 

 system in a species to which he gives this name, and gives a 



' A Paper read before the Royal Society of Edinburgh by Mr. J. T. 

 Cunningham, on Monday, May 16. 



figure of the animal opened along the dorsal median line. In 

 this figure four looped nephridia are distinctly shown, situated 

 behind the branchial region. The representation of the position 

 and character of these organs is perfectly correct so far as it 

 goes : they are the upper parts of the four nephridia belonging to 

 somites 6-9. But the paper I refer to does not describe the 

 nephridia, as it deals with another subject : they are shown in 

 the figure, and that is all ; and in the description of the figure 

 the organs are referred to as organs of generation. 



Keferstein {Ziitschrift fiir wiss. Zoologie, Bd. xii., 1862) men- 

 tions that the structure and number of the nephridia in T. conchi- 

 lega are the same as in T. gelatinosa, Kef. : in both cases he 

 says there are six pairs, each organ consisting of a tube bent on 

 itself, of which one half is darker, the other lighter : the organs 

 belong to segments 3-9. 



Cosmovici ^ gives an erroneous description of the organs : he 

 says there are two pairs without internal openings, which he 

 calls "organs of Bojanus," one of these situated in front of the 

 cephalic diaphragm, the other immediately behind it, each organ 

 having an external opening ; and two other pairs, each of which 

 has an internal as well as external opening, and is shaped like 

 an urn : the internal opening is large, and surrounded with a 

 circular lip. The gonad is attached to the posterior part of each 

 of these latter organs, which Cosmovici calls segmental organs, 

 and which he says serve as efferent excretory ducts. 



The species referred to by these three authors is the Nereis 

 conchilega of Pallas, Terebella conchilega of Gmelin ; and this is 

 called Lanice conchilega by Malmgren. My specimens were 

 identified from Malmgren's description, and there is no doubt of 

 the identity of my specimens with the species of that author ; 

 but there is room for some uncertainty regarding the specific 

 identity of the specimens referred to by the authors I have men- 

 tioned. For instance, Cosmovici identified his species by means 

 of Quatrefages' " Histoire des Anneles," 1865, and there it is 

 stated that the tube of Terebella conchilega possesses no hollow 

 fringes at its mouth : these fringes are always present in the tube 

 of Lanice conchilega, Malmgren. This species is distinguished 

 by some marked characters : two of them are the presence of a 

 large vertical lobe on the 3rd somite (second branchiferous) 

 and the coalescence of the ventral scutes usually present into a 

 continuous ventral plate. 



The true relations of the excretory system are as follow : — 

 Enumerating the somites from before backwards, and count- 

 ing the buccal as the ist, we find that the branchije belong to 

 somites 2, 3, and 4 : the first notopodial fascicle of capillary 

 setce is on the 4th somite, the third branchiferous ; the first 

 neuropodial unchiigerous torus is on the 5th : the neuropodial 

 tori are repeated on every succeeding somite to the end of the 

 body ; the notopodial fascicles occur only on seventeen consecu- 

 tive somites. There are trace 5 of transverse septa behind the 

 1st, 2nd, 3rd, and 4th somites, but none in the rest of the 

 thoracic region, which bears the notopodial fascicles. On dis- 

 section, four long double nephridial tubes are seen projecting 

 dorsalwards with the body-cavity ; the lower parts of these tubes 

 are covered by strands of the oblique muscles which pass from 

 the nerve cord to the neighbourhood of the notopodial bristles : 

 careful examination shows that these tubes belong to somites 



6, 7, 8, and 9. Their internal openings can be found imme- 

 diately behind the fascicle of bristles belonging to somites 5, 6, 



7, and 8 respectively, but their efferent tubes are seen to pass 

 down beneath the fascicles of somites 6, 7, 8, and 9. The lower 

 parts of these efferent tubes are very wide, and it is impossible 

 to separate them from one another. Beneath the fascicles of the 

 following four somites (10-13 inclusive) are seen membranous 

 nephridial sacs, which externally at least are inseparable from 

 one another. These sacs are simple, that is, they are not com- 

 posed of a tube bent on itself like the anterior nephridia : they 

 scarcely extend above the level of the oblique muscles, and no 

 internal opening or nephrostome can be found in them. In front 

 of the m; St anterior nephridium, that belonging to somite 6, 

 are seen traces of a rudimentary nephridium. In order to trace 

 out the relations of these nephridia more accurately, the anterior 

 part of a specimen was cut into a series of horizontal 'ongitudinal 

 sections, commencing with the ventral surface, and the reason 

 why the successive nephridia could not be isolated from one 

 another was seen on examination of these sections : the lower 

 parts of the efferent limbs of the four anterior normal nephridia, 

 in somites 6-9, and the whole of the nephridial sacs in somites 



^ " Glandes genitales et Organes segmentaires des Anneli-des polychetes' 

 (Arch, de Zool. Exp., t. viii., 1879-80). 



