i6 



NATURE 



[November 2, 1899 



many points. The unusually good preparations obtained by the 

 author have enabled him to throw much new light on some of 

 these disputed points. The eggs are laid in clusters or sheets con- 

 taining from one to two dozens, arranged in a single layer and 

 closely attached together with a white, mucus-like secretion, 

 which is at first very sticky, although it subsequently hardens, 

 Although hermaphrodite, Planarians reproduce by cross-fertilis- 

 ation. For the details of the author's observations, reference 

 must be made to the original paper. 



In Prof. Verrill's report on the Ophiuroids collected during 

 the Bahama Expedition of 1893 {Bulletin from Iowa Laboratory, 

 vol. v. , No. I ), the chief general interest centres round the 

 observations connected with the protective resemblances 

 developed by the feather-stars of the Bahamas. According to 

 the author, " most of these species with long, coiled arms, 

 adapted for clinging to the branches of gorgonian corals, are 

 adapted for imitating closely, in various ways, the forms and 

 colours of the corals on which they live. This must afford 

 them a considerable degree of protection against predaceous 

 fishes, in addition to the direct protection due to the stinging 

 powers of the corals themselves, which is sufficient to cause 

 most fishes to avoid them." Many fishes, it is added, have, 

 however, in all probability become immune against coral-stings, 

 and feed on hydroid polyps ; and the author argues that if this 

 be so, the additional protection afforded the feather-stars by their 

 resemblance to the gorgonias would be obvious. But, unless the 

 feather- stars form a specially tempting bonne-bouche and are 

 liable to be picked off separately, the obviousness of this does 

 not seem quite clear, since feather-stars and gorgonias would 

 be both consumed together by the fish. 



The importance now attached to preparing skins of small 

 mammals for study purposes according to a uniform plan fully 

 justifies the appearance of a paper on the subject by G. S. 

 Miller in the Bulletin of the U.S. Museum (No. 39). A list 

 of instruments and material required, as well as the details of 

 manipulation, are given ; and a plate illustrates the appearance 

 of the finished specimens. 



The November number of Science Gossip is particularly full 

 of interesting articles. Major B. M. Skinner gives a short ac- 

 count of the valley of the Tochi river which he explored during 

 the North-west Frontier campaign ; and an account of the for- 

 aminifera collected by him from the rocks in Waziristan is given 

 by Mr. Arthur Earland. The limestones fall naturally into two 

 divisions, (i) alveoline, (2) nummulitic, and the article is illus- 

 trated by photographs of rock-sections of both of these types. 



A SERIES of observations on the " focal depth," or as it is 

 sometimes called the penetrating power, of microscopic objectives 

 is given by Mr. Leon E. Ryther in the Journal of Applied 

 Microscopy for September. By plotting the magnifying powers of 

 various combinations as abscissae and the corresponding focal 

 depths as ordinates, a curve is obtained approximating to an 

 equilateral hyperbola indicating that in the author's experiments 

 the focal depth varied inversely with the magnifying power. 



J. Eriksson reprints from the Annales des Sciences Naturelles 

 a translation of an important paper, which appeared originally 

 in Swedish, on the brown rust of cereals. He proposes to 

 split up into six species the well-known parasitic fungus Puc- 

 cinia rubigo-vera, only one of which species is at present 

 known in the secidiospore stage. Of the six species described, 

 the first and second only are of great importance in agriculture, 

 the first being very destructive to rye, and the second being 

 apparently the only parasitic fungus which causes rust on wheat 

 in Europe, the United States or Australia. The paper 

 concludes with some practical suggestions for farmers. 

 NO. 1566, VOL. 61] 



The mineral resources of the Province of New Brunswick 

 form the subject of Part M of the tenth volume of the annual 

 report of the Geological Survey of Canada (1899). The subject 

 is dealt with by Dr. L. W. Bailey. At the outset he remarks 

 that if we except building-stones, gypsum, limestone, brick-clays, 

 and other materials applicable to building purposes, there are 

 but four substances that have been the basis of anything like 

 extended or successful mining operations. These are coal, iron, 

 manganese and albertite, and of these coal only is at the present 

 time being worked. There are, however, large tracts that are 

 still covered with unbroken forest, and consequently are but 

 little known. They comprise rocks whose geological age and 

 character suggest that they may be productive of useful minerals, 



A PROGRAMME of lectures received from the Hull Scientific 

 and Field Naturalists' Club shows that the Club is actively 

 engaged in creating and fostering a love of natural knowledge 

 within its sphere of influence. 



During this month the following popular science lectures^ 

 will be delivered on Tuesday evenings, at the Royal Victoria 

 Hall :— November 7, Mr. L. Fletcher, F.R.S., on "The Fall 

 of Stars from the Sky"; November 14, Mr. W. J. Pope, oa 

 "The Uses of Distillation"; November 21, Dr. J. W. 

 Waghorn on " Bad-Contacts : their application to telephones^ 

 and wireless telegraphy " ; November 28, Mr. Michael Sadler 

 on " A Brother of the Birds " (St. Francis of Assisi). 



The London Quarterly Review (Charles H. Kelly) publishes 

 a long article by "A Field Naturalist," in which Darwin's 

 observations and experiments on cowslips and primroses are 

 discussed, and the conclusion is arrived at that the evidence 

 brought forward by him is insufficient to establish the theory 

 that cross-fertilisation is necessary to the full fertility of flowers^ 

 "On the contrary," says the reviewer, " we are of opinion that 

 the primrose gives strong confirmatory evidence to Axell's view,, 

 that under natural and equal conditions, self-fertilisation of 

 flowers is both the legitimate fertilisation and the most 

 productive." 



A NATURAL consequence of the scientific activity of the 

 Liverpool Marine Biology Committee is the preparation of a 

 series of memoirs, edited by Prof. Herdman, on typical British 

 marine plants and animals. Each memoir will be concerned 

 with one type, and the forms selected for description will 

 chiefly be common Irish Sea animals and plants, of which na 

 adequate account already exists in text-books. Three of the 

 memoirs will appear before the end of this year, namely, 

 Ascidia, by Prof. Herdman ; Cockle, by J. Johnstone ; and 

 Echinus, by H. C. Chadwick. Others will follow in rapid 

 succession, and the complete series of special studies promises 

 to be of value to all marine biologists. 



The additions to the Zoological Society's Gardens during the 

 past week include a Sooty Mangabey (Cercocebus fuliginosus) 

 from West Africa, presented by the Rev. A. Clutterbuck ; a 

 Young Leopard {Felis pardus) from East Africa, presented by 

 Captain J. L. Stanistreet ; a Greater Vasa Parrakeet {Coracopsis 

 vasa) from Madagascar, presented by Mr. C. Hunt ; a Corn 

 Crake {Crex pratensis), British, presented by Mr. Collingwood 

 Ingram ; a Ringhals Snake {Sepedon haemachetes) from South. 

 Africa, presented by Mr. J. E. Matcham ; two Red-footed 

 Lemurs {Lemur rufipes, 6 ? ) from Madagascar, an Ichneumon. 

 {Bdeogale, sp. inc.) from Africa, a Westerman's Eclectus 

 {Eclectus westermani) from Moluccas, two Black-tailed Godwits 

 {Limosa aegocephala), European ; ten Salt-water Terrapins 

 {Malacoclemmys terrapin) from North America, deposited ; four 

 Common Squirrels (Sciurus vulgaris), European, purchased. 



