October i i, 1900] 



NATURE 



579 



condition of agriculture in Denmark, the happy position of which 

 is attributed in the report to legislation, education and co-opera- 

 tion. Visits such as that under consideration cannot, if properly 

 organised, fail to bring about useful results. 



Those interested in the phylogeny of the Vertebrata will be 

 pleased to hear of the discovery in the seas of Alaska of a new 

 representative of the Enteropneusta, in the form of a species allied 

 to the typical group of Balanoglossus. This new form, which it 

 is proposed to call Harrimania maculosa, is described by 

 Mr. W. E. Ritter in Part 2 of " Papers from the Harriman 

 Alaska Expedition," now in course of publication in the serial 

 last quoted. The new form leads its describer to conclude that 

 the notochord of the Enteropneusta is undoubtedly homologous 

 with that of the Vertebrata. It is specially noticeable in that it 

 consists of two parts ; the anterior corresponding with the same 

 structure in the other members of the group, while the additional 

 posterior moiety is connected with the esophagus. This latter 

 portion is peculiar in that it persists throughout life. Harri- 

 mania, which is considered to be the most primitive member of 

 the group, instead of burrowing like Balanoglossus, lives under 

 stones, where it often makes its way through the mud at the 

 plane of contact between the latter and the stone beneath which 

 it is concealed. While some examples were only found at ex- 

 treme low tide, others occurred much nearer high-water mark 

 than is the case with any other Enteropneusta. 



The last published number of the U.S. Monthly Weather 

 Review (June) contains a note by Prof. E. B. Garriott on the 

 extension of the Weather Bureau work, which constitutes one 

 of the most substantial advances in the history of that institu- 

 tion. The West Indian branch was established in 1898, and at 

 the present time practically all the cable islands and ports of the 

 West Indies and the Carribean coast of South America receive 

 advices regarding tropical storms. The West Indian observing 

 stations number thirteen, and hurricane warnings are displayed 

 at more than a hundred points. Telegraphic reports are now 

 also received from well-distributed Mexican stations. It is 

 believed that the reports received from the northern and western 

 parts of Mexico will lead to a better understanding of the 

 important storms which sweep north-eastward from the tropical 

 Pacific and cross the United States to the Atlantic. Reports 

 from the extreme north-west of Canada have been added within 

 the last two years and have furnished valuable data regarding 

 the movements of North Pacific storms. The Weather Bureau 

 has consequently reports from an area extending over more 

 than 42^ of latitude and 65° of longitude. The advantage 

 afforded by these widespread telegraphic stations can hardly be 

 over estimated. 



The Philosophical Magazine for October contains an inter- 

 esting paper by Mr. R. J. A. Barnard, of Melbourne, on the 

 annual march of temperature. The author has examined the 

 observations for forty years at Melbourne and has divided them 

 into two groups, 1859-78 and 1879-98. In each group the 

 average for every day is obtained and smoothed twice by re- 

 placing the temperature of each day by the mean of the five 

 consecutive days of which the particular day is the middle. 

 The results of the second smoothing show that in the second 

 week of March the temperature begins to drop rapidly, reaching 

 a secondary minimum for each curve on the 19th. It then rises 

 again to the extent of a^^ during the next week, reaching a 

 maximum on the 25th and 26th, the data being the same again 

 for both groups. The spells are not so marked as those found 

 by Dr. Rijkevorsel for Europe, owing probably to the more 

 uniform conditions of the southern hemisphere. The results 

 show that a period of less than forty years is not likely to give 

 any trustworthy information about spells, and that the division of 

 NO. 1615, VOL. 62] 



the observations for any particular place into groups of twenty 

 years and the comparison of them in the way specified appear 

 to be satisfactory methods of finding out whether such spells 

 really exist. 



The rise and fall in the level of a lake, produced by the 

 mechanical action of wind, is strikingly shown in a short 

 paper contributed by Prof. A. J. Henry to the U. S. Monthly 

 Weather Review for May. Continuous records of lake level at 

 four points, viz. Amherstburg, Ontario, mouth of the Detroit 

 River, and Buffalo Harbour, Lake Erie, were considered in 

 conjunction with continuous records of wind direction and 

 velocity and atmospheric pressure made at the Weather Bureau 

 offices in Detroit and Buffalo ; and a relation between the wind 

 and water is clearly shown when the two sets of records are 

 plotted under one another. It has been known for some years 

 that general winds, as distinguished from local winds, blowing 

 parallel to the longer axis of the main body of the lake, have a 

 tendency to heap up the water at the end of the lake toward 

 which they blow, and to depress it at the opposite end. Owing 

 to the convergence of the shore lines at Buffalo, the heaping up 

 of the waters in that harbour, under the influence of a south- 

 westerly wind, becomes a serious menace to the safety of wharf 

 and dock property. Likewise, owing to the shoal water at 

 either end of the lake, a decrease in the available depth in the 

 harbours and channels produces vexatious delays and frequent 

 groundings. 



Prof. Henry's examination of the facts referred to in the fore- 

 going note shows that when high water exists at Amherstburg it 

 is always low water at Buffalo. The synchronism of the times of 

 high water and low water at the two places is almost perfect. 

 The period of oscillation is likewise fairly constant, ranging from 

 six to eight hours for a half oscillation, and from twelve to six- 

 teen hours for a whole oscillation. The computed time of a 

 whole oscillation, assuming the lake to have a mean depth of 

 50 feet, is, roughly speaking, seventeen hours. While the in- 

 formation on the subject is as yet too fragmentary to admit of 

 drawing trustworthy conclusions, this much seems to be 

 apparent : the oscillations are stationary rather than progressive. 

 A wave of water is not propagated, in the ordinary sense of that 

 word, from one end of the lake to the other, but the whole lake 

 oscillates about a pivotal or nodal line, which, in the case of 

 longitudinal oscillations, may be said to cross the lake about the 

 longitude of Fairport, Ohio. Although there is no instrumental 

 evidence of the fact, it may be assumed that, as in the case of 

 similar oscillations in other land-locked bodies of water, the 

 oscillations at the nodal line are zero, increasing to a maximum 

 at the respective ends of the lake. Prof. Henry concludes by 

 saying that it is within the range of probability that the occur- 

 rence of the more pronounced oscillations can be forecast by the 

 Weather Bureau at no distant period. 



To the Entomologists' Monthly Magazine for October, Mr. 

 R. McLachlan contributes an abbreviated translation of an 

 article, by M. A. Lancaster, on the swarms of a species of 

 dragon-fly {Libellula quadrimaculata) which were observed in 

 Belgium on June 5 and 10 last. On both occasions the tem- 

 perature was very high, and the insects flew against the wind. 

 The translator is of opinion that nothing certain in regard to 

 the causes of these remarkable migrations has hitherto been 

 ascertained. "As a rule," he writes, " the multitudes are so 

 vast as to make it difficult to believe that all can have been 

 bred within a very limited area. On the contrary, it rather 

 looks as if the individuals in a certain initial locality, being 

 seized with an uncontrollable migratory impulse, were progres- 

 sively joined by others till the accumulations formed the ulti- 

 mate swarm. A part of the second swarm seems to have reached 

 England. 



