220 



KNOWLEDGE. 



[October 1, 1900. 



ravines, the contortions and overfolds in the Jurassic 

 beds can be clearly traced upon the great rock-walls. 

 The passage of fifty miles up the river lies almost 

 entirely in the limestones ; neai- its close we come out 

 abruptlv on the Kewer Cainozoic conglomerates of Jajce, 

 which contain pebbles of the rocks that form the Karst. 

 Here denudation has cleared out a sort of amphitheatre, 

 at the head of which the town and castle stand. Part 

 of this basin has been filled up by recent travertine, 

 vet another tvpe of limestone, which forms massive beds, 

 cut through by the Yrbas and the Pliva. The Moham- 

 medan town, climbing up a conical hill, is thus actually 

 built on material brought in solution from the Karst. 

 The modern waters are still adding to this deposit, 

 trickling through the interstices of the tufa, and forming 

 new films and stalactites in the clefts. 



Above Jajce, the wooded valley i"uns at first in the 

 Palseozoic shales, which tend to pass into mica-schists. 

 Now and then a brecciated limestone comes in, with 

 faults and slickensided surfaces, and probably also of 

 Palaeozoic age. ft Palaeozoic limestones are, indeed bent 

 up to form plateaux east of Bugojno, which repeat the 

 characters of the great Karst-Iand to the west. 



Between Donji Yakuf and Gornji Yakuf. two highly 

 typical Bosnian villages, the elongated " polje " of 

 Bugojno extends. The hills fall back on either 

 hand, and here and there across the level cultivated 

 land one can see the mouth of some gorge in the Karst, 

 guarded by a ruined tower. In late Cainozoic times, when 

 the basin came into existence, the streams from the lime- 

 stone plateaux speedily converted it into a lake ; but 

 their clear hard water flowed through it, bringing down 

 scarcely any matter in suspension. Consequently, the 

 freshwater molluscs, Limnctn and so forth, jj flourished 

 in the lake, and their activity formed the fine chalkv 

 limestone, the so-called "shell-marl," that ultimately 

 filled the basin. A tiiie alluvium, deposited in modern 

 days by the Yrbas, covers the central part of the area. 



The road up this part of the valley has a verv English 

 air, gently winding between fine old hedgerows, which 

 were planted in the Turkish days. Down among the 

 willows, a man and his horse are bathing together in the 

 stream, and the two figures are as simple and natural as 

 a scene from prehistoric times. In a small field, three 

 horses, tied to a post, run round and round, treading 

 out the corn ; while the winnowing is done, in a more 

 open area, by a turbaned peasant, who flings up the 

 grain with a shovel into the air. The stream shining 

 in the sunlight, the life of the Bosnian homestead, the 

 light wind blowing away the chaflt, and the far-ofiF 

 piping of some herd-boy seated in the shadow of the 

 woods — here you have the " polje " at its fairest, the 

 oasis set against the Karst. Above Gornji Yakuf all 

 this ceases; we plunge again into the beech-forests, and 

 begin the ascent of the watershed between the Black 

 Sea and the Adriatic, which has been chosen as the 

 natural boundary between Bosnia and the rugged Herce- 

 govina. The woods of beech and young oak cover the 

 lower hills completely, but leave long grass-slopes on 

 heights of five thousand feet or more. On the cnl 

 of the Maklen Pass (1123 metres), there is a little 

 clearing, and then we look out from the northern forest 

 into a new and rock-girt world. The mountain-side 

 drops steeply from our feet, and the Alpine road goes 

 down in windings, like a white serpent, to the mosques 

 and roofs of Prozor. The bare cliff of Triassic limestone 



on which we stand is succeeded by a park-like region, 

 again due to the presence of Newer Cainozoic beds ; 

 but beyond and above this smiling foreground rise, tier 

 upon tier, the craggy walls of the Hercegovina, cul- 

 minating in the Prenj planina, 7000 feet above the 

 sea. Seen from this distance, the country is clearly a 

 huge plateau intersected by ravines. Beyond Prozor. 

 we run abruptly into one of these gorges m the lime- 

 stone. There is just room for the road in the notch 

 through which we pass ; then we swing down and down, 

 curve after cui-ve, into the great Rama vale below. 

 Here we are lost among the rocks, driven on- 

 ward, like the stream, along the one passage opened 

 thi-ough the country ; now and again, what looks like a 

 knife-cut appears in the precipice on our left, where some 

 tributary has worked its way down from the level high- 

 land of the Karst, The ravine, in the heat of a Dinaric 

 day, is always deep in shade ; at its foot, we run out 

 into the still nobler valley of the Narenta. and halt for 

 the night under the Prenj crags in an amphitheatre 

 worthy of Tyrol. 



Here the way is open to the Adriatic, through the 

 great gorge that cuts across the Karst, past the barren 

 slopes of Mostar, and down to the marshes of the 

 Dalmatian shore. The sun beats upon the precipices, 

 and makes each cirque a white fiu-nace in the hills. The 

 river itself shrinks among its stone-banks, leaving on its 

 edges green and stagnant pools. The lizards, revelling 

 in the noonday glare, lie motionless on gleaming slabs 

 of rock ; far up. one may see an eagle, sailing across the 

 pale blue-purple of the sky. Perhaps it is time to 

 turn northward, to ci'oss the Ivan Saddle, and drop 

 through the cool dark woods to Sarajevo. 



t+ Compare Mojsiso* ics, GrundUnien, S;c., ))p. .58 aiul ")(>. 

 XX Moj?isoTics, iHd.. ]i. 6.3. 



ON THE RESPIRATION OF CERTAIN DRAGON- 

 FLY NYMPHS. 



By the Rev. ARTHrR East. 



The question as to the method of respiration amongst 

 the various members of the family of the Odonata is 

 admittedly an obscure one, and the following obser- 

 vations will, it is feared, not tend much to elucidate 

 matters, but are intended only to draw attention to a 

 point which does not appear to be generally recognised. 

 That the question is one requiring careful investigation 

 may be infeiTed from the following instance. One family 

 of the dragon-fly group is furnished with certain leaf- 

 like appendages to the extremity of the abdomen, which 

 are known as the caudal lamellse. These organs are 

 closely connected with the tracheal system, no doubt 

 acting in the same way as the gills of a fish, and extract 

 the air dissolved in the water — in fact the nvmph 

 breathes by means of them. But of the three caudal 

 lamellje which these Zygopterid nymphs normally rely 

 upon for supplying them with air, which is as essential 

 to them as it is to us, often one, or two, or even all 

 three are missing; lost to their owners by some un- 

 toward accident. Of one member of this group, Mr 

 Lucas, in his book on the British dragon-flies, even 

 writes that Agrion puella, as bred by him, vsuallij lost 

 its lamellse before emergence, and yet, strange to sav, 

 the nymph appears quite as happy without its breathing 

 apparatus as with it, and only suffers incont-enience, 

 apparently, from the loss of its propeller, which function 

 • the caudal lamellae also fulfil. It is believed that the 

 process of breathing may be performed through the skin. 

 A nymph recently placed in water, together with a small 

 quantity of indigo, in order to see whether any stream 



