NA rURE 



[November 5, 1908 



Tanaka's paper is represented by a small eel-shaped fish 

 allied to Simenchelys, but scaleless. 



In view of the attention that is now being concentrated 

 on the house-fly as a disseminator of disease, the appear- 

 ance in the October issue of the Quarterly Journal of 

 Microscopical Science of the second part of Mr. C. G. 

 Hewitt's paper on the structure, development, and habits 

 of the species is extremely opportune. In this portion the 

 author deals with the breeding-habits and the anatomy and 

 development of the grubs. After full reference to the work 

 of previous naturalists, it is concluded that horse-manure 

 is the favourite breeding-place, although decaying organic 

 matter of almost any kind may form the nidus for the 

 eggs. The rate of development depends entirely on 

 temperature, and it is important to notice in this connec- 

 tion that the substance in which the eggs are laid is 

 generally in a state of fermentation. The shortest time 

 for development — from laying to the appearance of the 

 perfect fly — is eight days, but the period may be extended 

 over several weeks. There are three grub-stages. From 

 June to October is the chief breeding-season, although 

 under favourable conditions flies may be fertile all the 

 year. The flies become sexually mature in from ten to 

 fourteen days after their first appearance in the world, and 

 they may begin to lay within a fortnight. Each fly may 

 lay six batches of ova, each containing from 120 to 130 

 eggs. The " bionomics " of the species will be discussed 

 in the third and final part of the paper. 



The spoliation of the Falls of Niagara, on account of 

 the abstraction of the water for electrical and other works, 

 forms the subject of an e.Kceedingly interesting article in 

 the October number of the Popular Science Monthly, by 

 Dr. J. W. Spencer, who has devoted much attention to 

 the study of rivers generally. After referring in more or 

 less detail to the various power-stations connected with 

 Niagara, the author notes the very great lowering of 

 the water-level above the falls as the result of this tapping. 

 As an example of the enormous amount of water taken by 

 these works, it is stated that when in June last a single 

 company temporarily stopped its take of 8000 cubic feet 

 per second, the water in the basin rose no less than 

 6 inches, and at the edge of the American falls 12 inches. 

 " The preservation of the falls," continues Dr. Spencer, 

 " is now a question of inches. Under the conditions as 

 set forth [i.e. as regards further tapping], the whole of 

 the Horseshoe Falls will have shrunken from a crest-line 

 of 2950 feet to 1600 feet, and their diameter will have 

 been reduced from 1200 to 800 feet. They will then be 

 entirely within Canadian territory, as the boundary line 

 will become uncovered, leaving a narrow strip of rock 

 between Goat Island and the great cataract. If the full 

 franchise be used, the American Falls, which are 1000 feet 

 across, will have their southern half drained, and will be 

 further broken up into narrow sheets or strings of water." 

 The preservation of the falls, it is added, now depends 

 entirely upon the Governments of Washington and Ottawa ; 

 it is sincerely to be hoped that they will so regulate matters 

 as to retain the world-renowned falls for all time. In a 

 second article, by Mr. R. H. Arnot, the industries con- 

 nected with the falls are described at length. 



A THIRD part of the current botanical volume of the 

 Philippine Journal of Science (July) contains a list of plants 

 ^collected near Lake Lanao Mindaneo by Mrs. Clemens, and 

 identified by Mr. Merrill ; also a series of identifications 

 of Philippine plants, in which Mr. R. A. Rolfe is associated 

 with Mr. Merrill. A Ranunculus closely allied to the 

 NO. 2036, VOL. 79] 



Australian Ranunculus lappaceits, the genera Hoppea and 

 Hemiphragma furnishing an Indian element, and the 

 genus Spiraeopsis known only from the Celebes, are geo- 

 graphically interesting. Mr. F. W. Foxworthy records 

 the identification of " lumbayao " timber as the product 

 of Tarrietia javanica. The allied Tarrieiia sylvatica 

 furnishes the timber " durigon," that is better known, but 

 here reported inferior. 



The discovery in Siam of a new genus of the unique 

 order Rafflesiaceas is recorded by Dr. C. C. Hosseus in 

 Engler's Bolanische Jahrbiicher (vol. xli., part ii.). The 

 plants of this order are parasitic herbs, consisting of a 

 vegetative structure reduced to a network of cellular 

 threads ramifying in a host plant, and of flowers sub- 

 tended by a few scale leaves. The new genus, Richt- 

 hofenia, falls into the tribe Raffiesieae, together with the 

 genera Raffiesia, Sapria, and Brugmansia. It is similar 

 to Rafflesia in the possession of a plurilocular ovary, but 

 agrees with Sapria as regards its bilocular anthers. It 

 thus forms a connecting link between the two genera. Its 

 habitat, too, lies between the Malayan home of Rafflesia 

 and the Himalayan locality of Sapria. 



It is fully recognised that considerable risks attach to 

 the formation of pure forests owing to the liability of 

 destruction by the rapid spread of insect or fungus pests. 

 American investigators have provided another reason in 

 favour of mixed plantations in so far as they attribute 

 weight to soil deterioration by the excretion of toxic 

 material from the roots. The editorial note in the Indian 

 Forester (September) touches upon these points, and 

 further arguments applying to conditions in India in favour 

 of intermixing trees of less value are adduced by Mr. P. 

 Lushington. Firstly, there is the fuel value to be con- 

 sidered, but, in addition, it is pleaded that " worthless " 

 species provide cover for the ground, or may serve to 

 draw up the high-class trees, or in the case of evergreens 

 help materially to check forest fires. 



The Oxford list of British plants is one of three such 

 publications recently issued, the other two being a list 

 compiled by the botanical authorities at the Natural History 

 Museum, South Kensington, and the tenth edition of the 

 London catalogue. The South Kensington list is the most 

 restricted, as the critical forms of Hieracium, Rubus, 

 Euphrasia, and Salix are omitted, all varieties, also extinct 

 and various introduced plants. A special feature is the 

 reference to the original determination of each species. 

 The Oxford list is, on the other hand, the most com- 

 prehensive, registering varieties and aliens of all kinds, or 

 foreigners as some might be called. The London cata- 

 logue approximates to the Oxford list, differing chiefly in 

 a greater discrimination of aliens. There is, however, one 

 notable point of distinction in the latter, as Mr. Druce 

 refuses to accept the list of special generic names passed 

 by the Vienna Congress as worthy of retention. While 

 respecting his opinion, it seems a mistake not to abide by 

 the decision of the congress. To coordinate the species in 

 the three publications may well be left to the ardent 

 systematist. Doubtless all three will find supporters, 

 besides being used for comparison. Certainly the 

 Clarendon Press could have found no botanist better versed 

 in the intricacies of the British flora than the author they 

 have selected. 



The Journal of the Meteorological Society of Japan for 

 July contains a discussion, by T. Ogawa, of the climate 

 of Fusan (south-east of Corea) from observations since 

 1904. The seasonal means of air temperature are : — 



