6^,2 



NA TURE 



[October 27, 1904 



the new specimens. The superintendent has to report the 

 theft during the year of a quantity of gold jewellery, of 

 which no trace has been discovered. 



Zoological papers received from America in our last 

 week's batch include a treatise on Acarina, or mites, by 

 Mr. N. Banks ; notes on Hawaiian reptiles, by Mr. R. C. 

 McGregor; on reptiles from Missouri, by Mr. J. Hurter; 

 two molluscan papers by Mr. F. C. Baker, and a third, by 

 Mr. T. L. Casey, on the gastropods of the family Pleuro- 

 tomarida;. The first two are published in the Proceedings 

 of the U..S. National Museum, the rest in the Transactions 

 of the .St. Louis Academy. 



The American Naturalist for July and .August contains 

 a report of the proceedings of the first annual meeting of 

 the eastern branch of the American .Society of Zoologists, 

 held in Philadelphia in December last. Of its other con- 

 tents, perhaps the most interesting is a paper, illustrated 

 with a coloured plate, by Mr. M. M. Mayland, on the 

 colour-variation displayed by a small local form of the 

 common marine gastropod Neritina virginea, which inhabits 

 "Salt Pool," near Port Henderson, Jamaica, and is also 

 found in a fresh-water stream in the same island. In the 

 one instance the dwarfing is attributed to the extra salinity 

 of the water, in the other to its freshness. The diversity in 

 colour and colour-pattern of both the normal and the dwarf 

 forms is extraordinary, and perhaps unparalleled, but all the 

 variations intergrade. 



Mr. H. Ingle, who recently went from the Yorkshire 

 College to take charge of the chemical work of the Trans- 

 vaal Department of Agriculture, contributes a short paper 

 to the department's Journal on the composition of Transvaal 

 soils. About a dozen typical soils from different parts of 

 the country have been examined by him. He finds that, as 

 compared with English soils, Transvaal soils are somewhat 

 markedly deficient in nitrogen and phosphoric acid, but he 

 very properly points out that their fertility cannot be judged 

 of entirely by European standards. The soils are in reality 

 much better than analyses made in the ordinary way would 

 lead us to suppose. When Dyer's method was employed 

 the proportion of available to total phosphoric acid and 

 potash was found to be high, much higher than is usually 

 the case in this country. As a set-off to the natural poverty 

 of the soils in nitrogen, Mr. Ingle indicates that the receipts 

 of combined nitrogen from the atmosphere are probably 

 higher in South .Africa than in England. In February and 

 March of this year, for example, the rainfall collected in 

 Pretoria brought down about 2 lb. combined nitrogen per 

 acre, whereas at Rotharasted the average annual receipts 

 of the soil from this source ainount to some 4I lb. only. 

 In addition to nitrogenous manures, Transvaal soils require 

 compounds supplying phosphoric acid and lime, and of the 

 manures imported basic slag is suggested as likely to be 

 most economical. 



As a contribution to the volume which was prepared in 

 honour of Dr. P. Ascherson's seventieth birthday, Dr. Stapf 

 has written a sketch of the distribution of the grasses in 

 South Africa. Two main subdivisions are distinguished, 

 a smaller group of forms extending into the tropics and a 

 larger endemic South African group, which includes sub- 

 tropical and temperate forms. The tropical and subtropical 

 species are allied to the palacotropic flora of tropical Africa ; 

 the temperate element has affinities with some grasses of 

 Asia Minor and Australia, but how and when they have 

 been connected is not obvious. There is an accumulation 

 of temperate grasses, many of thein endemic species, in the 

 NO. 1826, VOL, 70] 



Cape district, which suggests that the land formerly extended 

 further south. 



.AccoROixc to Circulars received, the Department of Agri- 

 culture in the United States, through the Bureau of 

 Forestry, offers the services of its officers to farmers and 

 landowners as advisers in the matter of tree planting and 

 forest conservation. As for the conditions under which this 

 help is given, preliminary examination is defrayed by the 

 department, but if the undertaking is sufficiently extensive 

 to require a survey and special plans, the owner has to pay 

 actual and necessary expenses ; the object is to prove to 

 timber-land owners that conservative methods of lumbering 

 will pay. 



In the Revue Scientifique of October i Prof. A. Thauzifes, 

 of P^rigueux, resumes the discussion of the question as to 

 the manner in which carrier-pigeons find their way home. 

 In the same journal for March 24, 1900, Mr. de Cyon ex- 

 pressed the opinion that the sense of smell determines the 

 proper direction, and it is to the refutation of this theory 

 that the portion of the professor's article published in the 

 issue before us is devoted. Among other points cited to 

 disprove the olfactory theory is the fact that young pigeons 

 are frequently unable to discover the whereabouts of their 

 dovecot despite the overpowering odour issuing there- 

 from. In the concluding portion of his critique, published 

 in the issue of October 8, Prof. Thauzifes discusses the theory 

 that homing pigeons orientate by a " sense of attitude." 

 That is to say, they preserve a sense of direction by the 

 number of times they have turned en route. After urging 

 several strong and apparently fatal objections against this 

 theory. Prof. Thauzifes suggests that it may nevertheless 

 contain a germ of truth. For the present, however, the 

 " homing instinct " must remain a puzzle. 



The current number of the Annals of the Royal Botanic 

 Gardens, Peradeniya, contains several papers of interest, and 

 helps to emphasise the necessity for a thorough study of the 

 problems presented by tropical vegetation. A paper by Mr. 

 R. H. Lock is of particular value in this connection. By 

 a careful study of the rate of growth of giant bamboos, Mr. 

 Lock has found that the difference in rate of growth between 

 day and night is due, not to the alternation of light and 

 darkness, but to the change in the conditions of moisture, 

 the air being damper at night. The curve of rate of growth 

 follows that of moisture and rainfall with most surprising 

 closeness. The second part of Mr. Herbert Wright's paper 

 on Diospyros contains figures of the flowers, &c., in this 

 genus, and shows the great need for study of tropical plants 

 in the field as well as in the herbarium. The number also 

 contains a paper by Dr. Svedelius on Enaliis acoroides, the 

 life-history of which he studied in the straits between Ceylon 

 and India. The floral mechanism shows a very interesting 

 difference from that of Vallisneria, correlated with the fact 

 that Enalus is a marine plant. The male flowers are caught 

 at low water and drawn under as the tide rises, pollination 

 taking place subsequently. .Another paper by Mr. R. H. 

 Lock contains a preliminary statement of the results of the 

 first " Mendelian " breeding work carried on in the tropics, 

 and gives a number of interesting results with peas and 

 maize, mentioned in last week's Nature (p. 601). 



The report of the Meteorological Commission of Cape 

 Colony for the year 1902 shows that the interest taken in 

 the progress of meteorology by the public is increasing. 

 Rainfall is observed at 500 stations ; this number includes 

 58 second order (barometric) stations and 27 third order 

 (thermometric) stations. The report also contains sum- 



