January 3, 1895] 



NATURE 



Dr. Anton Reichenow, of the Royal Zoological Museum 

 of Berlin, has just completed a memoir on the birds of German 

 East Africa, which will form a portion of the third volume of 

 Stuhlmann's work, " Mit Emin Pascha in's Ilerz von Afrika." 

 The memoir gives an account of 728 species of birds which have 

 been recorded up to the present time, by German naturalists 

 and other explorers, as met with within the limits of the German 

 Protectorate. The remaining portions of the same volume, 

 which are in progress under the editorship of Dr. Mobius, will 

 complete the account of the vertebrates. The fourth volume, 

 under the same editorship, will be devoted to the invertebrates, 

 and the fifth, edited by Dr. Engler, to the botany of the 

 German East-African Protectorate. Vol. vi. will give an 

 account of the geography and meteorology, and vol. vii. of the 

 geology and mineralogy of the same country. It may be asked 

 how long we shall have to wait for a similarly complete account 

 of British East Africa ? 



The "Zoological Record" for 189J, which has just been 

 published by Messrs. Gurney and Jackson, for the Zoological 

 Society of London, has appeared rather later than usual. 

 Its bulk shows us at once that the quantity of work accom- 

 plished by zoologists in 1893 is not inferior in amount to that 

 ■of the immediately preceding years. Some of the recorders, 

 we may be allowed to point out to Dr. Sharp, commence their 

 " Records" with an interesting account of the principal events 

 that have taken place in their special branches of the subject 

 during the year of record. Others altogether neglect this very 

 desirable piece of information. It would be well to insist that 

 a page or two of introduction, containing matter of this de- 

 scription, for the general information of zoologists, should be 

 prefaced to every section of the "Record. ' Many readers who 

 clo not care to study the special portion, would like to get a 

 general notion of what has been going on. 



A.N' exhaustive bacteriological investigation of the AUona 

 water-supply has been recently published by Dr. Reinsch. 

 Although the results obtained are not specially novel, yet they 

 are of importance as confirming the researches of other investi- 

 gators. It is pointed out that whilst the layer of slime which 

 forms on the surface of sand-filters plays an important part in 

 the retention of microbes, yet another factor must be most care- 

 fully watched if a satisfactory filtrate is to be obtained. This 

 factor is the depth of the column of fine sand through which the 

 water is made to pass. It was first called attention to by Dr. 

 Percy Frankland in 1886, in the course of his examinations of 

 the London water supply ; and since that time investigations 

 made at Zurich and elsewhere, have shown that it is not advis- 

 able to reduce the layer of sand below 30 cm. Reinsch states 

 that it should never be less than from 40-60 cm. high. This 

 investigator also states that to encourage the formation of 

 surface-slime, the filters, after the water is first run on, should 

 be left undisturbed for twelve hours, and that the neglect of 

 this simple precaution exercised an important influence on the 

 filtrate. 



Some vexed points in the developmental history of medusje 

 have been attacked in a masterly manner by Miss (?) Ida II. 

 Hyde, who publishes a paper on this subject in the Zeilsihrijl 

 f. win. Zoologie (\ii. Iviii. iv.). The material for her investi- 

 gations consisted of embryos of ihree different species of Auic/ia 

 and Cyaiiea. The formation of the endoderm is shown to vary 

 considerably in difierent species and even in the same species. 

 In A. mar«inaUs the endoderm is formed by multipolar 

 delamination, in C. arctica by delaminalion at the pule of the 

 blastopore. In A.flaviJula the endoderm sometimes arises by 

 embolic gastrulalion, with or without the participation of a few 

 immigrant or delaminated cells, but in other cases arises almost 

 MO. 1314, VK.. si] 



exclusively from immigrant and delaminated cells, the invagin- 

 ated element being relatively insignificant. These differences 

 of origin in the same species seem to be determined by local 

 conditions of temperature and salinity of the water. The 

 author regards multipolar delaminalion as the most primitive 

 of the various processes by which the endodermal digestive 

 chamber is brought about. The development of the Scyphuta 

 larva is then traced, and the author is able to confirm Goette's 

 account in all essential points. There is a true stomadxum, 

 and the invaginated ectoderm also takes part in the formation 

 of the four septa and of the gastral filaments of the Scyp/iosloma. 

 The points of affinity which have been raised between the 

 Scyphomedusas and the Anthozoa thus acquire new and 

 substantial support from Miss (?) Hyde's researches. 



A NEW periodical, Archiv fiir Entiuic kelitngsmechanik Jtr 

 Or'anismen (Leipzig: Engelmann), of which the first number 

 lies before us, is intended by the editor. Dr. W. Roux, to pro- 

 vide a medium for the publication of researches upon the causes 

 of the phenomena of organic development, as distinct from the 

 mere normal order of the phenomena themselves. The journal 

 is to furnish an organ for that branch of biology which has 

 been variously termed the " mechanics of development " 

 and "causal or experimental morphology." In the hands of 

 Roux, Driesch, Hertwig, Chabry, Wilson, and others, the 

 methods of this school, which are above all things experimental, 

 have been applied to various problems in development with 

 much success and with the most interesting results. It is there- 

 fore to be hoped that the publication of a journal specially 

 devoted to experimental morphology will lead to a considerable 

 increase in the number of investigations in this promising field. 

 In the present number the editor gives an introduction on the 

 objects, methods, and scope of the branch of biology the new 

 Archiv represents, and a number of interesting researches are 

 published on the " cytotropism " of isolated blastomeres, on 

 compensatory hypertrophy of organs and regeneration, and on 

 the origin of the forms of joints. 



The young cocoa-trees in one part of the island of Jamaica 

 are suffering from the attacks of a caterpillar. A correspon- 

 dent calls our attention to a letter in the Jatnaica Gleaner, in 

 which Mr. W. Fawcett, the Director of Public Gardens and 

 Plantations, regrets that the museum is at present without the 

 services of a curator, who might be able to give some informa- 

 tion as to the best means of dealing with the caterpillars, and 

 the remedy he suggests for keeping down the plague is by hand- 

 picking. In this connection, a summary of a report on a plague 

 of caterpillars at Hong Kong, in the current Kezu Bulletin, is 

 of interest. These caterpillars appeared on pine-trees, and 

 belonged to a large moth (Metanastria punctata. Walker). 

 The trees attacked were those of Pinus sinensis. Lamb, very 

 largely planted in the island for re-foresting purposes. Active 

 steps were taken by the Government to destroy the pests, by 

 establishing stations where the caterpillars could be received 

 and paid for by weight. The caterpillars were caught by 

 shaking the trees and picking them off the ground. From the 

 report summarised in the A'eiu Bulletin, it appears that the 

 plague lasted two months. The quantity of caterpillars col- 

 lected weighed nearly thirty-six tons, and a large number of 

 cocoons were also destroyed. .Altogether it is estimated that 

 thirty-five million insects were destroyed. Mr. W. J. Tutcher, 

 who drew up the report, says that the methods employed for 

 the extirpation of the scourge were decidedly successful ; so that 

 if similar measures are promptly taken at Jamaica, the cater- 

 pillais may be kept under. 



In measuring the volume of a solid by immersion in a liquid, 

 it is usual, after withdrawing the solid, to find what volume of 

 liquid is required to re-establish the former level. The well- 



