Ii6 



NATURE 



[October io, igi3 



occupying I iges, is a chronoloj 



lorphology of the veg< tative or repro- 



,l u , ■;-,,, is 1 1 . 1 1 . -il in detail in 



i i , , ■ 1 1 1 . ,1 " Biological Notes " deals with 

 he distribution ol the seed • to 

 n - ei ologii al note the author's 



own observations. 



si RINE I- U NA IN THE FAR EAST.' 



'pill-: two memoirs before us contain the firsl five 



A of a series of reports upon material coll 



for purposes of comparison with a corresponding 



,., in the Indian fauna, bj Dr. Vnnandale in 



dn fakes ol a. I t, namely, in Lake Biwa 



in fapan, in Tai Hu Lake in the Yangtse Delta and 

 in Talc- Sap, a lagoon on the eastern coast ot the 

 Malay Peninsula: with them is incorporated a short 

 critical dissertation on Oriental Batr-achia in general. 



Lake Biwa, with an ana oi 269 square miles, lies 



among hills aboul fort) miles distant from the sea; 

 . ,, is more than 200 It. deep in many parts and rea< ties 

 a depth of $20 ft. in some places, and as then' is con- 

 siderable difference in summer temperature between 

 th< open surface and the depths, then' is some variety 

 in its biological conditions. Tai Hu, about sixty miles 

 in length and in breadth, is a muddy lake of uniform 

 tions, nowhere exceeding 12 ft. in depth; though 



j miles from the sea and its water is quite 



fresh, it- fauna contains a distinct marine or estuarine 

 , 1, ment. Tale' Sap differs from the other two lakes in 

 lying on the seaboard and having a narrow sea-inlet; 

 [ike the Chilka Lake in Orissa, it consists of two dis- 

 tinct basins oi unequal density— though the inner basin 

 is fresh, or practically so, throughout the year— and so 

 nts variable conditions; the greatest depth of the 

 main fresh-water portion is about 16 ft. 



The collections described in the present instalments 

 .,,,. the Polyzoa in pan (Entoprocta and Ctenosomatous 

 Ectoprocta), the Mollusca of Lake Biwa, and the 

 Hydrozoa and Ctenophora, all by Dr. Annandale him- 

 self, the aquatic Oligochaeta by Col. J. Stephenson, 

 I.M.S., and the aquatic Hemiptera by Mr. C. A. 

 Paiva. Most of the reports are distinguished by atten- 

 tion to anatohiii il details and to biological interpreta- 

 ii fact. 



1 tie Polvzoa comprise five species bom Tale Sap and 



two from Tai Hu. Two of them (Triticella pedicellata 



Paludu ella elongata) have nol before been rei orded 



from tropical latitudes. A third noteworthy form, 



[3 akin to Lo os itides, but differing in the 



ement of the muscles of the stalk, is distin- 

 1- a new genus, Chitaspis. 



[ollusca of Lake Biwa include twenty-nine 

 vhich eleven are restricted to this lake and 



e peGUliar tO Japan. Most of the 



iieaa, ITinoibis, \ ivipara, Bithynia) 

 or (e.g. (Vnodonta, \ alvata) pala;- 

 arctic, Melania and Corbicula, of common 



occurreni il and subtropical latitudes. The 



authoi disti . rupicolous community of species 



quite distim I inhabiting ihe mud and sand 



in shallow wati ngeries of species restricted 



to the depths, latter being the only repre- 



sentatives of Pisid \ Ivata occurring in the 



lake. 



Among the Hydro 1 are Cordylophora 



lacustris, from Tai H p cies from the 



brackish parts of Tale Sap. tion of a new 



genus of Hydromedusae, Vsei the Gangetii 



Delta, is also included; this the autl 1 1 suspects to be 



1 "Zoological Results of a Tour in Ihe Fer ) litedbyDr. N. 



ale. Memoirs of ihe Asiatic Society of 1 vi , pp. 1-74 



NO. 2554, VOL. I02] 



the sexual gi i ttion oi the curious hydroid Annulella 

 described by Ritchie from that part of Bengal. 



\ ng the aquatic Oligochajta, Branchiura sowcrbyi 



and Limnodrihu socialh were found in association 

 h , is in [ndi 1; a new species of Chajtogaster com- 

 mensal in sponges is described, and a new genus Kawa- 

 muria — a Branchiura without gills and having the 

 penis-sac providi '1 with a penis — from the depths of 

 Lake Biwa. Col. Stephenson also describes a new 

 species of Criodrilus, found at the remarkable depth 

 of I.No ft. in this lake. 



The aquatic Hemiptera an- for the most part com- 

 mon Oriental forms ; but Microvelia sexualis, from 



J . 1 1 • Sap, i new species of Hydrometrid represent- 

 ing a genus hitherto known only from North America. 



CARBONISATION RE [CTIONSS 



IT is difficull to obtain clear information about the 

 tea. tlons in carbonisation bj the direel distillation 

 ol coal in the laboratory, especially aboul minor, 

 though important, products sue h as toluene , i» nzi n. , 

 etc., of which ihe quantities available become exces- 

 siveh small. Therefore the author, in conjunc 

 with Dr. S. F. Dufton, chose to investigate the 

 stability of individual compounds in differem atmo- 

 spheres when passed over heated coke, with a time 

 ol contact ol the- same order as met with in car- 

 bonising practice. The behaviour of the compounds 

 was dependent on conditions of temperature and con- 

 centration, apparently in accordance with the laws of 

 chemical dynamics. Benzene, at varying partial pres- 

 sures in an atmosphere of nitrogen, which was 

 assumed to be inert, showed signs of incipient decom- 

 position ai 550' « '., leading to the prddui tion ol diphenj I. 

 At highei temperatures this was more extensive, and 

 f-diphenylbenzene also appeared. The former con- 

 densation ai least is reversible. Benzene in an atmo- 

 sphere of hydrogen yielded much less diphenyl under 

 otherwi-e similar conditions, and al 8oo c C. is SCarO 

 decomposed at a concentration of 5 per cent. Iw 

 volume, while diphenyl in an atmosphere of hydrogen 

 is reduced to benzene. This doubtless account- foi 

 the practical non-occurrence of diphenyl in coal-tar, 

 although this substance is readih formed from benzene 

 in the absent.- of hydrogen. Benzene did not yield 

 naphthalene or unsaturated compounds. At9O0°C., even 

 in hydrogen, benzene was extensively broken down 

 with the formation of carbon. Toluene in nitrogen 

 shows signs oi decomposition at 550° C but then an 

 now two possibilities reactions through the nucleus 



anil al-o through the side chain. The product is more 



complex, a solid being formed, which was idei 

 stilbene it 'I I .< ', 1 1 ,),, and also an oil. Al 750' C. de- 

 composition was more extensive, naphthalei 

 anthracene being identified among a number ol other 

 products, (in substituting hydrogen lot nitrogen the 

 decomposition was much accelerated, but with the pro- 

 duction 01 nd methane and smallei quantities 

 of solids. III. formation of stilbene, which occurs 

 with the liberation of hydrogen, is inhibited. Methane 

 and benzene n act in the - lion to form 

 toluene-, but 011K very slowly. Tims hydrogen pro- 

 tects benzene from decomposition, whereas it decom- 

 poses toluene-, inn in the sense of breaking oil the side 

 chain while hindering moleciulai condensations with 

 elimination ol hydrogen, which are a characteristic 

 effeel of heal on the lowei aromatic hydrot 

 Tin- xylenes resi mble toluene in behaviour, while- in -..I 

 is reduced bj hy dt ogen al 750 < '. to toluene, and nei 1 s- 

 sarily to ' : so; The- importance of atmosphere 



idie William Young Memorial Lecture of the North British 

 Association of Gas Managers, Glasgow. September 6, 19:8, by Prof. John W. 

 Cobb. 



