494 



NA TURE 



[March 26, 1908 



that the principal differences between willow-titmice and 

 marsh-titmice are that the feathers on the crown and 

 forehead are longer and more loosely constructed in the 

 former than in the latter. The edges of these feathers are 

 -also glossy black in the marsh-titmouse, thus causing the 

 crown to be glossy and of a deeper blackness than that 

 of the willow-titmouse, which is brownish or sooty black. 

 In the latter, again, the tail is distinctly graduated, instead 

 of being almost squared. To these differences Mr. Booth 

 adds the darker rufous colour of the flanks and under- 

 parts of the willow-titmouse. 



The evolution of the elephant forms the subject of an 

 Interesting article by Mr. R. S. Lull, in the March number 

 of the American Naturalist. Starting with the fact that 

 they made their first appearance in the Fayum district of 

 Egypt during the Eocene, the author considers it probable 

 that the proboscideans remained in Africa during the Oligo- 

 cene, although we have no direct evidence to that effect. 

 Be this as it may, the four-tusked mastodon (Tetrabelodon 

 angustidens) made its appearance in the early Miocene of 

 Mogara and Tunisia, whence it migrated by means of a 

 land-bridge connecting Tunisia and Sicily with Italy, and 

 thence by way of Greece, into Asia. Having reached that 

 continent, it apparently gave rise to the Indian Mastodon 

 cautleyi and M. latidens, from which in turn sprang the 

 primitive, or stegodont, elephants, and from these again 

 elephants of the modern type. Later on the typical 

 elephants themselves migrated westwards to Europe, and 

 thence to Africa, while in the other direction they travelled 

 "by way of Bering Strait to America. Hence we are led 

 to conclude, as has been previously pointed out by Mr. 

 Lydekker, that while the Proboscidea originated in Africa, 

 the modern African elephant is of .'\siatic parentage, and 

 was an immigrant into the land of its forefathers in com- 

 pany with the ancestors of the giraffes, okapis, and ante- 

 lopes which now dominate Ethiopia. It is added that, 

 next to man, elephants have been the greatest travellers 

 of all mammals, having reached practically all parts of the 

 world. 



Under the heading of " Investigations on the Develop- 

 ment of Trypanosomes in Tsetse-flies and other Diptera," 

 Prof. E. A. Minchin gives in the March number of the 

 Quarterly Journal of Microscopical Science the results of 

 his investigations during a sojourn in Uganda as a member 

 of the commission on sleeping sickness. In the author's 

 opinion, it may now be admitted that trypanosomes 

 undergo development (as distinct from multiplication) in 

 invertebrate hosts, more especially tsetse-flies. It is, how- 

 ever, remarkable that, whereas Trypanosoma briicei under- 

 goes a complete cycle of development in at least one kind 

 of tsetse, this is not the case with T. gambiense. The 

 explanation suggested is that Glossina palpalis, the only 

 kind of tsetse found at Entebbe, is not the proper host of 

 7'. gambiense, a suggestion supported by the fact that 

 sleeping sickness is a disease of comparatively recent 

 introduction into Uganda. That the Gambian trypano- 

 some has a proper host of its own cannot be doubted, and 

 it is probable this may be a native of the Congo, where 

 it is suggested further investigations on sleeping sickness 

 might advantageously be conducted. In Uganda T. 

 : unhicnse merely commences its developmental cycle in 

 '■. palpalis, by which, in that district, it is transmitted 

 I the human subject in a purely mechanical and direct 

 ■ iinner.- 



Wii have received from Messrs. Zeiss a pamphlet de- 

 scriptive of Siedentopf's paraboloid condenser, with which 

 an exceedingly well corrected dark ground illumination 

 NO. 2004, VOL. 77] 



may be obtained for microscopical work. For observation, 

 medium and high-power dry objectives should be 

 employed. The apparatus is particularly adapted for the 

 observation of such minute objects as bacteria and their 

 flagella, spirocha^tes, &c., in the fresh and living state, 

 and for photographing the same under these conditions. 

 We have also received Messrs. Zeiss 's general catalogue 

 of apparatus for ultramicroscopy, which contains much 

 matter of interest. 



In the Journal of Hygiene for January (vol. viii., No. i) 

 Miss Harriette Chick contributes an interesting article on 

 the theory of disinfection. She shows that a very complete 

 analogy exists between a chemical reaction and the process 

 of disinfection, one reagent being represented by the dis- 

 infectant, and the second by the protoplasm of the 

 bacterium. In the case of anthrax spores, the course of 

 disinfection apparently proceeds in accordance with the 

 well-known equation lor a unimolecular reaction, if 

 numbers expressing " concentration of reacting substance 

 are replaced by " numbers of surviving bacteria." A non- 

 sporing organism, B. paratyphosus, shows a departure 

 from the simple law owing to permanent differences in 

 resistance to disinfectants among the individual organisms, 

 the younger bacteria proving to be the more resistant. 

 The process of disinfection is influenced by temperature in 

 an orderly manner, and the well-known equation of 

 .\rrhenius can be applied. Some evidence was obtained 

 that, in disinfection with mercuric chloride, a toxic com- 

 pound is formed between the metal and the substance of 

 the bacterial cell. 



The principal article in the Bulletin du Jardin Imperial 

 Botanique of St. Petersburg (vol. vii., parts v.-vi.) is an 

 account of the soil and vegetation of the district of Jaila, 

 in the Crimea, communicated by Mr. A. Krischtofowitsch. 



Tamarind seeds are to be reckoned among the fairly 

 nutritious plant products that have been reported to 

 provide food during periods of famine in India. The pulp 

 of the fruit is an esteemed ingredient of certain condi- 

 ments. The kernels of the seeds when freed from the 

 skin and roasted furnish a not unwholesome flour suitable 

 for mixing with cereals to make small cakes. Further 

 details and analyses are given in the Agricultural Ledger 

 (No. 2, 1907) prepared by Mr. D. Hooper and published 

 by the Government of India. 



The annual publication " One and .All Gardening " 

 has reached its thirteenth issue. ."Among the numerous 

 articles, Mr. H. J. Wright furnishes an account of garden> 

 teaching in schools, in which he provides a working plan 

 for laying out a school garden, and summarises the pro- 

 gress made in different counties. Mr. S. L. Bastin con- 

 tributes a note on the method of retarding flowers. The 

 editor takes for his subject the formation of garden 

 associations to stimulate horticulture in country and town ; 

 in this connection Mr. F. H. Stead records a remarkable 

 development of gardens in the borough of Walworth, where 

 last year more than one hundred gardens were entered 

 for competition at the local flower show. 



The fauna and flora of the Snares and Auckland Islands 

 form the subject of an ecological descriptive sketch con- 

 tributed by Dr. L. Cockayne to the New Zealand Times 

 (December ii, 1907). The author refers to the evidence 

 furnished by the animal and plant life on the Snares in 

 favour of the view that when a land area is curtailed 

 the exceptional species most frequently survive in the 

 struggle for existence, and so reduced areas generally 

 contain numerous endemic species. The meadows of the 



