April 4, 1901] 



NATURE 



555 



latest observations thirty-nine species of Rhopalocera were 

 recorded within, roughly speaking, a ten mile metropolitan limit, 

 but that of these he only knew of Pieris rapae, P. napt, Vattessa 

 atalanta, V. urticae, and perhaps one or two others which could 

 strictly speaking be said to inhabit the metropolis itself. Mr. 

 A. J. Chitty said that Pieris Irassicae had occurred, and that he 

 thought Vanessa polychloros might be added to the list of those 

 open to experiment. Mr. G. H. Verrall advocated the intro- 

 duction of tropical and other foreign species in the great 

 conservatories of Kew, where, without danger to the plants, 

 they would be objects of great beauty and attractiveness, and 

 Mr. Merrifield, while recognising the difficulties arising from 

 soil, climate and surroundings, expressed his belief that certain 

 hardy species would successfully resist their bird enemies. 



Royal Microscopical Society, March 20.— Mr. A. D. 

 Michael, vice-president, in the chair. — Messrs. Staley and Co. 

 sent for exhibition a Bausch and Lomb Camera Lucida. It was 

 described in the Journal of the Society last December, and is 

 intended for reproducing an object diagrammatically, natural size. 

 — Mr. E. M. Nelson read a paper on the working aperture of 

 objectives for the microscope, in which he showed that in re- 

 cording delicate observations it was advisable to state the 

 precise ratio of the utilised diameter of the objective to the full 

 available aperture. He then proceeded to explain the different 

 methods by which this ratio, which he termed the working ratio, 

 or W.R., could be measured. Dr. Tatham confirmed Mr. 

 Nelson's views in regard to the necessity for recording the work- 

 ing aperture of objectives, and expressed his appreciation of 

 the value of the methods proposed by the author for obtaining 

 this measurement. — A paper, by Mr. H. G. Madan, on a 

 method of increasing the stability of quinidine as a mounting 

 material, was read by Mr. Nelson in the absence of the author. 

 Mr. Madan found that by keeping quinidine heated to a certain 

 temperature for a considerable time it was converted into colloid 

 quinidine, which condition it had retained for a year ; but whether 

 the tendency to revert to the crystalline form was entirely over- 

 come, time alone could show. Mr. Karop said of all media, 

 quinidine, on the whole, was the best yet discovered for mount- 

 ing diatoms, but it was very troublesome on account of its 

 tendency to crystallisation. He hoped the material prepared as 

 suggested by Mr. Madan would be marketed.— Mr. Rousselet 

 read a paper on some of the rotifera of Natal, by Hon. Thos. 

 Kirkman, illustrated by mounted specimens shown under micro- 

 scopes. Mr. Rousselet had appended a technical description of 

 Pterodina trilobata, one of the rotifers mentioned in the paper, 

 a mounted one of which was among those exhibited ; an excel- 

 lent drawing of this rotifer, by Mr. Dixon-Nuttall, was also 

 shown. — Mr. W. H. Merrett read a paper on the metallography 

 of iron and steel, demonstrating the subject by the exhibition of 

 a large number of lantern-slides of sections of different classes 

 of these metals under various conditions of hardness, stress, &c. 

 The methods by which these sections had been prepared and 

 polished were also explained. 



Royal Meteorological Society, March 20. — Mr. W. H. 

 Dines, president, in the chair.— Dr. Hugh Robert Mill delivered 

 a lantern lecture on climate and the effects of climate. He re- 

 marked that climatology is as much a branch of geography as of 

 meteorology, in fact more, for it not only deals with the distri- 

 bution of atmospheric conditions over the earth's surface, which 

 is a geographical question in itself, but all the varieties of climate 

 that give individuality to different countries are produced by the 

 disturbing or controlling influence of land forms. After making 

 a few remarks on the principles of scientific photography and also 

 calling attention to spurious photographs, the lecturer proceeded 

 to distinguish between " weather" and " climate." Weather 

 is the condition of the atmosphere at any moment with regard 

 to wind, warmth, cloud, electricity and precipitation ; whilst 

 climate may fairly be called the average weather of a place. 

 Dr. Mill then exhibited on the screen a large number of photo- 

 graphs which he had himself taken in many countries, in order 

 to illustrate the peculiarities of climates in which heat, cold, wind 

 and rain respectively predominate, showing how the varying 

 conditions of climate created by the greater land forms are 

 respondel to by the various adjustments of minor land-forms 

 and of plants, and how they are taken advantage of by man. 

 Cambridge, 



Philosophical Society, March 4.— Prof. Macalister, presi- 

 dent, in the chair. — The ossification and varieties of the occipital 

 bone, by Prof. Macalister. These deviations from the normal 



NO. 1640, VOL. 63] 



type, which occur in one out of every four skulls, may be 

 divided into two great groups, (i) those depending on variations 

 in the union of the five elements of the squama, supra-occipital,' 

 interparietal right and left and pre-interparietals right and left ; 

 (2) the second group consists of the variations due to the develop- 

 ment of new centres of ossification in the lambdoid suture. — 

 On the fifth book of Euclid's elements, by Dr. M. J. M. Hill — 

 E.xhibition of Mr. Graham Kerr's method of reconstructing objects 

 from thin sections, by Mr. J. S. Budgett. — Note on the colour 

 vision of the Eskimo, by Mr. W. H. R. Rivers. Ten men 

 and eight women from Labrador were tested with Holmgren's 

 wools and found to have normal colour vision. In naming 

 colours a limited number of terms were used which were exten- 

 sively modified by suffixes to express differences of shade and 

 tint of colour. The language was exceptional in possessing 

 names for green and blue which were as definite as those for red 

 and yellow, but resembled most other primitive languages in 

 having no word for brown. — Note on the influence of e.xternal 

 conditions on the spore-formation oi Acrospeira mirabilis (Berk, 

 and Br.), by Mr. R. H. Biffen. Chlamydospores of this fungus 

 sown on pea extract gave rise to a sterile mycelium ; on Klebs' 

 solution and 5 per cent, glucose or cane sugar to numbers of 

 intercalary sporangia ; on beer-wort to sporangia and chlamydo- 

 spores ; on chestnut extract to endoconidia and chlamydospores 

 — the former being in the greatest abundance when the extract 

 was most dilute. Sowings of the spore-balls gave very similar 

 results, the chlamydospores being replaced by spore-balls except 

 in the case of beer-wort, where "ascogonia" were formed. 

 Intermediate forms between the loose spiral "ascogonia" and 

 the closely coiled helices of the spore-balls could be raised by 

 transferring the mycelium from chestnut extract to beer-wort. 

 Increasing the rate of transpiration caused the chlamydospores 

 to become smooth and thick-walled, while diminishing it caused 

 them to become smooth and thin-walled, instead of being rather 

 thick and warted. The envelope of the spore-balls instead of 

 being a single layer became several layers thick on checking the 

 rate of transpiration. — On a reserve carbohydrate, which pro- 

 duces mannose, from the bulb of Lilitim, by Mr. J. Parkin. 

 Besides starch, the bulbs of several species of the genus Liliiim 

 examined contain another reserve-carbohydrate which exists as a 

 sort of mucilage in the cell-sap. The sugar obtained from it by 

 hydrolysis with weak acid is mannose. — Notes on new and 

 interesting plants from the Malay Peninsula, by Mr. R. H. Yapp. 

 The only partially explored mountain ranges of this region 

 possess a very rich flora, unaffected by the presence of introduced 

 species such as form a marked feature of the vegetation of the 

 inhabited districts of the plains. A number of the specimens 

 exhibited (which were chiefly collected on one of these moun- 

 tains) are probably new, and belong to various natural orders, 

 chiefly among the gamopetalous Dicotyledons. An interesting 

 and little known fact is the storage of large quantities of 

 naturally filtered water in the hollow internodes of several species 

 of bamboo. The paper concluded with a brief account of two 

 curious epiphytic ferns, whose fleshy stems are tunnelled by 

 galleries inhabited by ants'; forming, in fact, living ants' nests. 

 — The prevention of malaria, by Dr. J. W. W. Stephens. This 

 paper, after a brief historical account of the discovery and the 

 investigation of the malarial parasite, described the researches of 

 Dr. Christophers and the author on the disease in several locali- 

 ties on the west coast of Africa. The result of the work there 

 done leaves no doubt that malaria is avoidable under the con- 

 ditions of life in West Africa. — On the effects of a magnetic 

 field on the resistance of thin metallic films, by J. Patterson. 

 A. C. Longden, in the Physical Review, xi, 2, 40, described a 

 method of making standard high resistances from thin films of 

 metals deposited on glass by means of the kathode discharge. 

 He has shown that the resistance of these films is much greater 

 than that calculated from the ordinary specific resistance of the 

 metal. The author has made experiments to determine what 

 effect a magnetic field would have on the resistance of a film 

 deposited in this manner from a bismuth kathode. The results 

 obtained show that the change of resistance in the magnetic 

 field is entirely different from that of ordinary bismuth. A film 

 of cobalt I "4 X I "3 cm. with a resistance of 682*2 ohms was made, 

 but no change in a field of 27,500 lines could be detected. — On 

 the theory of electric conduction through thin metallic films, by 

 Prof. J. J. Thomson. The author applies the theory, developed 

 by him in a report to the International Congress of Physics at 

 Paris in 1900, to the case of electric conduction through thin 

 metallic films. He shows that when the thickness of the film 



