520 



NATURE 



[March 31, 1892 



metallurgy, and engineering, but a large increase in connection 

 with the departments of modern languages, geology, chemistry, 

 physics, and physiology. 



The Rugby School Natural History Society has now been at 

 work for twenty-five years, and its report for the year 1891 

 shows that it is still full of vigorous life. The geological 

 section, which lapsed ten years ago, has made a fresh start, and 

 the meteorological, the architectural, and the photographic 

 sections are slated to be "in a flourishing condition." The 

 editors have added to the report an index of all the papers and 

 records which have been published by the Society from the 

 beginning. 



With regard to the influence of electricity on the growth of 

 plants, a series of experiments made by Prof. Aloi on Lacttua 

 Scariola, maize, wheat, tobacco, and beans, indicate that atmo- 

 spheric electricity exercises a beneficial influence on vegetation ; 

 that the electricity of the soil has a similar influence on the 

 germination of seeds ; and that the less luxuriant vegetation of 

 plants which grow in the neighbourhood of trees is in great part 

 due to the diminution of temperature. 



The effects of earthquakes on vegetation have been investigated 

 by Signor A. Goiran, in the case of the seismic disturbances which 

 occurred last June throughout Northern Italy. He found in 

 this instance the uniform result to be to induce a more rapid 

 germination of seeds, and a more rapid growth of the young 

 plants, giving rise to a more luxuriant vegetation in the pastures, 

 arable lands, vineyards, and shrubberies, accompanied by an 

 unusually deep green colour of the leaves. These results he 

 believes to be due, not to the direct influence of the tremor, but 

 to three secondary causes, viz. (i) an increased production of 

 carbon dioxide ; (2) a diffusion of nutrient fluids through the 

 soil, acting as a kind of natural manuring ; (3) an increased 

 production of electricity. In other instances earthquakes have 

 apparently had an unfavourable influence on vegetation ; but 

 this Signor Goiran believes to be due to their having been 

 associated with a long period of drought. 



Oi" the recently published Indian Miueuru Notes one of 

 the most interesting papers is on the wild silk insects of India. 

 It is by Mr. E. C. Cotes, and is intended to serve as a supple- 

 ment to a previous paper on cultivated silk-producing insects. 

 A small amount of silk is spun by the caterpillars of most moths. 

 The only groups, however, which contain species whose silk is 

 at all suited for utilization are the Salurniidre and the Bomby- 

 cidse, and the whole of the Indian species belonging to these 

 groups, therefore, have been included in the present report, 

 though many of them do not produce sufficient silk to be of any 

 use. So much, however, has of late years been said about the 

 wild silk insects of India, and such exaggerated opinions have 

 been expressed as to their value, that it has been thought best 

 to deal exhaustively with the matter, so as to clear the ground 

 and show precisely how the question really stands. 



The Royal Agricultural and Commercial Society of British 

 Guiana has been discussing the question whether an Agricultural 

 College should not be established in the colony. At a recent 

 meeting Mr. Jacob Conrad brought forward a motion to the 

 effect that a Committee should be appointed to petition the 

 Government on the subject. He failed, however, to obtain the 

 support of a mrjority. Mr. Darnell Davis thought it desirable 

 that the question should be discussed, but could not see how 

 anything practical would come out of it unless some kind phil- 

 anthropist found the money. Agricultural Colleges were very 

 expensive, and he did not think the Government could be asked 

 to do anything, as it would mean the imposition of additional 

 taxes. He thought that every sugar plantation in the colony 

 was really an agricultural school. 



NO. I 170, VOL. 45] 



Mrs. Zelia Nuttall contributes to the new number of the 

 Internationales Archiv fiir Ethnographic a learned and in- 

 teresting paper on ancient Mexican shields. She divides them 

 into the following groups: — (i) Plain, unadorned war-shields 

 of several kinds, used by the common soldiery. (2) Gala-shields, 

 indicating the military rank and achievements of chiefs. These 

 seem to have been indiscriminately used in warfare or feasts and 

 dances. Their general structure seems to have been alike in 

 either case, though they may have been more or less light and 

 strong. Shields of this category sometimes reproduced one or 

 more features of the military costume, body-painting, and 

 adornments pertaining to each grade. (3) Shields, presumably of 

 the supreme war-chief, exhibiting in picture-writing the name 

 of his people or his personal appellation. Nothing certain is 

 known about this group, but its existence seems vouched for by 

 a series of indications. (4) Shields pictured in the codices with 

 deities only, exhibiting their emblematic devices or reproducing 

 features of their symbolic attire. Such shields seem to have 

 been carried, in religious dances and 'festivals, by the living 

 images of the deities in whose honour they were celebrated. 

 (S) Shields of most precious materials, with strange and elabo- 

 rate designs, described in the inventories. As they are not 

 mentioned elsewhere, it is not possible to state anything de- 

 finite about them, but it is obvious that they were intended for 

 the use of individuals of supreme rank. The beautiful shield 

 preserved at Castle Ambras, near Innsbruck, belongs to this 

 group. It is the only known specimen with a valid, though 

 shadowy, right to the title of "Montezuma's shield." 



According to Mr. A. Sidney Ollift", who writes on the sub- 

 ject in the Agriadtttral Gazette of New South Wales, the 

 " metropolis" of the plague locust of New South Wales is in 

 the western district, especially in the great plains between the 

 Lachlan and the Darling Rivers. The breeding-grounds of 

 locusts in Australia are as extensive as those of the Rocky 

 Mountain locust, and are found in similar situations. The eggs 

 are deposited in vast quantities in the earth, close beside one 

 another, frequently over a large tract of country. Usually these 

 breeding-grounds occur in sandy soils or in high dry places, 

 but occasionally they may be found on the banks of a creek. 

 At the end of September last, during a hurried visit to Ren- 

 mark, in South Australia, Mr. Olliff" found the bare sandy 

 banks of a small creek riddled with small holes from which the 

 newly-hatched locusts had but just escaped. Swarms of young 

 locusts had previously been observed by him near Wentworth, 

 making their way from the bare places in which they were 

 hatched to the richer pasturage. The U.S. Entomological 

 Commission has carefully investigated the various ways in 

 which these pests can be most effectually dealt with ; and a 

 condensed account of the results is presented by Mr. Olliff for 

 the benefit of Australian farmers. 



The Marine Biological Association, Plymouth, has issued a 

 new price-list of zoological specimens. This cancels the pre- 

 vious list. The specimens are suitable for class or laboratory 

 examination, and for museum purposes. They are kept in 

 stock at the Plymouth Laboratory, and are to be obtained on 

 application to the director. 



The following arrangements have been made for science 

 lectures at the Royal Victoria Hall during April : — April 5, 

 Henry M. Bernard, on "Life in Russia"; April 12, A. H. 

 Fison, on "The Compass Needle"; April 26, Captain Charles 

 Reade, on " The British Navy." 



Messrs. Macmillan and Co. have issued the sixth edition 

 of Sir Henry E. Roscoe's well-known " Lessons in Elementary 

 Chemistry." The fifth edition, which has been repeatedly re- 

 printed with slight corrections, was published in 1886. The 

 author has tried to introduce into the present edition all the 



