156 



NATURE 



{Dec. 19, 1878 



occurred in about ten minutes. An atmosphere contain- 

 ing one per cent, of the gas was found to prove fatal 

 within half an hour. In the case of a large female rabbit, 

 o'2 per cent, caused death in thirty-three minutes. In 

 these cases tlae most marked symptom was that of great 

 increase in the number of respirations. Before death, 

 respiration became slow and laboured, and convulsions 

 resembling those of opisthotonus occurred. The ventricles 

 of the heart became most powerfully contracted. Where 

 the strongest dose was administered, the effect on the 

 heart was most marked, and the lungs appeared un- 

 affected. When small quantities of the gas were used, 

 within a very short time the animals began to show signs 

 of suffering from intense irritation of the skin, scratching 

 and biting at it incessantly. Afterwards the creatures 

 seemed to become drowsy, and assumed a very peculiar 

 attitude, sitting down on all-fours, the back bent upwards, 

 and nose pushed back\vards between the fore-paws, so as 

 to bring the forehead against the floor of the cage ; a rat 

 in this position looked very much like a curled-up hedge- 

 hog. A fatal result occurred when the quantity of gas 

 was so small as i to 5120. In no case could the odour of 

 the gas be detected in any organ of the body after death. 

 The gas did not appear to exert any local action on the skin. 



Structure and Affinities of Charace.e. — This 

 difficult problem has been the subject of recent discussion 

 in the pages of Trimen' s Journal of Botany. The first 

 paper was in the July number, by Mr. A. W. Bennett, 

 who gave his reasons for dissenting from some gene- 

 rally accepted vaews of the structure of Chara, and from its 

 assignment by Sachs to a place among the Carposporeae, 

 He objects in the first place to the use of the term " pro- 

 embryo "i(V'orkeim) for 'the immediate product of the 

 germination of the spore, the homologue of the protonema 

 of a moss, and not of the pro-embryo nor suspensor of 

 Selaginellaceae and Phanerogams. The term sporangium 

 is also frequently misapplied to the, nucule, which is in 

 reality an archegonium. The so-called "sporocarp" 

 is formed before and not as the result of fecundation. 

 Finally, Mr. Bennett maintains that Characes differ from 

 all the other higher cryptogams in the absence 'of any 

 alternation of generations, the nearest affinity being with 

 Muscinese, which they approach in their organs of repro- 

 duction. In the September number Prof. Caruel expresses 

 his agreement with Mr. Bennett in removing the Characeas 

 from the Carposporese, but differs in his interpretation of 

 the structure which is the immediate product of germina- 

 tion, the homology of which with the protonema of 

 mosses he contests. He places them in a separate class 

 of their own, intermediate between phanerogams and 

 vascular cryptogams. Finally, in the number for Decem- 

 ber, Mr. S. H. Vines has a very elaborate essay on the 

 subject. He agrees with both the previous writers in 

 separating the Characeae from the CarposporeiE. and with 

 Caruel in disputing the homology of the "pro-embryo" 

 with the protonema of a moss, but on the other hand 

 again considers their nearest affinity, though remote, to 

 be with Muscineas. His principal object is to show that 

 the "pro-embryo" is in reality the embryo of the plant, and 

 that it constitutes in itself the non-sexual generation or 

 sporophore, homologous with the sporogonium of mosses, 

 notwithstanding the apparently anomalous fact that it 

 never produces spores. For such a structure he proposes 

 the term " aposporous sporophore," and compares it to 

 the "apogamous" oophore or prothallium of Ptcris 

 cretica and some other ferns, which are anomalous in not 

 producing se.xual organs of reproduction. , . ,^ 



GEOGRAPHICAL NOTES 

 The fifty-sixth supplement to Petermann's Mittheil- 

 tmgen has just been pubhshed, and consists of a masterly 

 treatise on Deltas, by Dr. G. A. Credner, of Halle. The 

 author shows the importance of deltas in reference both to 

 geography and geology, and discusses carefully the real 



import of the term. He then, in the first part of his work, 

 treats of the Formation, Structure, Growth, and Distribu- 

 tion of Deltas under the heads of (i) Limit and Form of 

 the Delta ; (2) Formation and Condition of the Delta 

 Surface ; (3) Size of the Delta ; (4) Its Power ; (5) Its 

 material ; (6) Architecture ; (7) Rate of its Growth ; (8) 

 Results of its Growth; (9) The Age of Deltas ; (10) 

 Number and Geographical Distribution of DeUas ; (i i) 

 Classification of Deltas. The second part treats of the 

 various causes of the origin of deltas, the causes and con- 

 ditions of their formation, in which the author discusses 

 various processes of great geological interest. Three 

 sheets of maps accompany this most important paper, 

 showing, among other points, the, various deltas of the 

 world. 



We are glad to learn of the early appearance of a work 

 published in Russia under the editorship of M. Semenoff, 

 President of the Geographical Society at St. Petersburg. 

 The title is " Illustrated Russia," and it will give a geo- 

 graphical, historical, ethnographical, and statistical de- 

 scription of the country. We notice among the very 

 numerous collaborators all the names well known in the 

 Russian geographical world. The work will contain four 

 folio volumes of sixty to seventy sheets each, and it will 

 be accompanied with numerous illustrations, engraved by 

 the best European firms. Another work of the same kind 

 is undertaken by M. Mordovtseff— " The Ukraine (Little 

 Russia) : its History and its People." It will be on the 

 same plan as the well-known work on " B.ohemia : its 

 History and its People." 



We are also glad to notice the appearance of the last 

 volume of the " Works of the Ethnographical Expedition 

 sent by the Russian Geographical Society." This volume 

 deals with the south-western provinces of Russia. The 

 expedition was undertaken in 1869, finished in two years, 

 and the printing of the reports, which occupy seven large 

 volumes, has taken since 1872. 



We find in the Izvestia of the Russian Geographical 

 Society a notice of the journey of M. Mayeff in Southern 

 Bokhara, last August. After having reached Karshi with 

 an embassy sent to the Emir by the Governor-General of 

 Tashkent, M. Mayeff visited the mountain pass, Ak-bash, 

 which goes from Tenga-khoram to the Kerchak River, 

 and to the great and wealthy village, Kuitan : thence he 

 proceeded by the pass Tenga-daval to Shir-abad. The 

 Kerchak River and its tributary, Kuitan-daria, both mighty 

 mountain streams, were previously quite unknown. The 

 Tenga-daval cleft cuts through the whole mass of the 

 Kuityn-tau, the south-western part of Hissar ridge. 

 From Shir-abad M. Mayeff, going further south, crossed 

 the great Pashkhund ridge, reached the Surkhan river at 

 Kakaity, and traced its banks down to Regar and Sary- 

 djuy. Thence he returned to Shahri-sabs by a very bad 

 route, hardly practicable even on horseback, along the 

 rocky banks of the wild stream, Sengri-dagh. The sur- 

 veys made during this journey are a most important 

 acquisition for the geography of Central Asia ; the high- 

 lands of Bokhara, quite unknown until now, will soon 

 receive on our maps an outline in accordance with 

 nature. 



The last number of the Izvestia of the Russian Geo- 

 graphical Society contains a report, by Capt. Sidensner, ■ 

 on the possibility of a water communication between the 9 

 tributaries of the Obi and Yenissei ; a very interesting 

 paper, by M. Miclucho Maclay, on the Pelew archipelago, 

 being a description of the people, its customs, administra- 

 tion, and religion ; a necrology of M. Chaslavsky ; and 

 several notes : — On M. Mayeft's journey to Southern 

 Bokhara, on the Russian cruises to the Obi and Yenissei, 

 and especially statistical ones on printing in Moscow, on- 

 trade, ports, and telegraphs in Japan, and on the popula- 

 tion and manufactures in governments Tula and Nijnir. 

 Novgorod. 



