400 



NATURE 



[August 22, 1895 



system of dry land (such a s}-stein was rather an extensive 

 archijielago than a continuous continent) ; thb last was a}piin 

 di\ndeti into two s)-stems : an Arctic and Occidental one, com- 

 prising North America, together with the northern parts of Asia 

 and Kurope, and an Indian one, communicating with South 

 Europe. The former was the home of the Cer\ida', the 

 rhinoceroses and most other Perissodaclyls, the latter that of the 

 Ca\icoms and elephants. \'er)' few mammals of Indian origin 

 migrated into .\merica ; much more from the .Vrclic system into 

 India. The same seems to be the case for ants. Myrvucina 

 is perhaps the only North .\merican genus of Indian origin 

 (Tetramorium iitsfitiim being doubtless introduced by man), 

 whereas a number of .\merican-.\rctic genera, sub-genera and 

 species-groups, as j)^r//;<ri<)t^'.r/Hy, Messor, Myriiiua, Camponottts 

 pennsykanicus, &c., are more or less far diffused in India and 

 -Vfrica, Mymiica reaching Borneo, and Messor the Cape of Good 

 Hope. 



In Europe, the study of the Baltic and Sicilian amber proves 

 that the .\rctic fauna went down from the north, as a host of 

 conquerors, invading the lerritor)' formerly occupied by other 

 people. I believe that, in Miocene times the North .\merican 

 fauna was much like the actual cosmopolite and Arctic jiart of 

 the recent fauna, and might have included a number of forms 

 actually extinct. As in the I'liocene a bridge was put between 

 North and South America, an invasion of neotropical forms took 

 place, walking from south to north. But it is not improbable 

 that other forms migrated in the opposite sense, and descended 

 from North America into the neotropical region. I suppose 

 that such was the case for the genus Pogoiwniyriiiex, perhaps 

 also for Doryniyrmex^ Foretius^ and several species of Cam- 

 ponotus. It is not improbable that other penera from North 

 .\merica migrated southward, and later Ix'came extinct in their 

 primitive home. The recent work of Mr. Scudder on Tertiary 

 Curculionid.T; of North .\merica seems to confirm this view , some 

 of these fossil twetles belonging to genera now living only in 

 South .\merica. It is probable that a number of insects, actually 

 regardcxi as typical memliers of the neotropical fauna, inimi- 

 grated from North -America, as it is proved by paheontology for 

 several mammals, as, for instance, the llama and alpacca of 

 the Pampas. 



The North .\mcrican origin of some South .\merican ants was 

 suggested by Prof. H. von Jhering,' in a |ia|x;r publi.shed last 

 year. The author endeavours to sustain, by the study of the 

 ants, his theory of the multiple origin of actual neotropical fauna. 

 I agree in many points with him,^but I must recognise that the 

 Formicida- afford but little evidence in favour of his \-iews. 

 Actually, the ants of South America are distributed chiefly in 

 relation to the climate and vegetation, no strong obstacles being 

 put to the wide dissemination of the species, some of which 

 range from Central America or from Mexico to Paraguay and 

 kio Grande do Sul. Chili is, however, .in isolated country, 

 which we may call " a continental island," although it is not 

 .surrounded by water. If we should take the Chilian fauna as a 

 standard for the primitive fauna of v. Jhering's .Archiplata, that 

 should have Ijeen a very |»or one, like the fauna of New Zea- 

 land, with which it offers a striking resemblance. The most 

 characteristic feature of the Chilian ant fauna is the occurrence 

 of peculiar species of Aloiiofitoriitrn^ like those inhabiting 

 Australia and New Zealand, and of the genus Melophoriis, found 

 only in .'\u.stralia and New Zealand. These facts corrol)orate 

 the hypothesis of a Cretaceous or Eocene connection Ijetween 

 South America and .Vustraiia. 



New Zealand ap|x-ars as a bit of old .Australia, quite free from 

 later Papuan or Indian intrusions, like Madaga.scar, which, as an 

 isolated part of old Africa, has received but a lew immigrants, 

 when, at the Pliocene c|>och, a stream of Indian life entered into 

 the .Ethiopian continent. Prolmbly Chili may be consitlered as a 

 |«rt of anz-ient Archiplata, secured from (luyanean and Bra7.ilian 

 ini . the heights of the Corilillcra, but having preserved 



01 i]ilete set of the original .\rchiplalean faun.!. 



I • facts for the purix>se of making the main con- 



r' ^lleci.^l work known to a wide public. Exact 



kn ^ : the exotic faun.-e, and es|x:cially of the fossils, may 



enable us m future to carry further these incomplete and in |)art 

 hypfrthctical results. Similar studies made on single groups of 

 animaU and plants by specialists, which do not only accumulate 



' H. von Jli»Ti"S " r>t' AiT^'iirn v-)n Kio ( Ir.indc du Sul." (Herlincr 

 r-! ■■ • ' ■ '■ ■ ,46. 1894.) 



ich I cinnot accept, refer chiefly 

 ■ * .V. In lhc?< poinl« I think lh.-it 



by blind statistical work names of families, genera, and species, 

 but deal with them, knowing the value of each, are highly de- 

 sirable. Summarising and integrating the single results will 

 build up an exact knowledge of paUeogeography, and of the 

 origins and interrelations of the fauna; and florve of the world. 



C. Emery. 



A NEW FILM HOLDER. 



^JO outdoor photographer can take a rough survey of the past 

 few years without feeling some astonishment at the rapid 

 progress made in nearly every branch of his art. The amateur 

 is no doubt indirectl) res|x>nsible for nuich of this advance i 

 for it is through him that other brains have been set to work 

 to satisfy all his many and variotis wants, in the way of instru- 

 ments and accessories, to lighten his task at every step. 



The camera, which a few years Kick was a heavy, clumsy and 

 awkwaril instrument, is now of a light aiul hamly construction, 

 capable of being used in many cases w ithout the triixxl. Stops 

 are now more generally of the Iris type, thus eliminating all 

 |»ssibilities of lo.ss or of leaving them behind ; while plate- 

 holders are now supplied ca|>al)le of holding a dozen or more 

 plates, and necessitating the use of only one dark shutter. 



The introduction of the film has brought us, however, into a 

 new era : but the full benefit of this improvement can only be 

 best ajipreciated by those who make use of their cameras while 

 travelling. 



Hitherto it ha.i been imiwssible to make satisfactory use of 

 the enormous advantages of celluloid flat films over glass plates ; 

 but now we have before us a holder which seems to give satisfac- 

 tion, and which should prove a boon to phi>t(^raphcrs in general. 



A holder to Ik' really efficient shonhl Ik; readily adaptable to 

 any ordinary camera ; it must contain a. large quantity of films. 



NO. 1347. VOL. 52] 



Fir.. I. — Magazine .-iiui receiver, separated. 



and when complete and loaded should not be any larger or 

 heavier than the three double backs (lighter if possible); and, 

 finally, should \x [irovided with some means of swiftly and 

 automatically changing the |X)sitions of the exposed films. 



Such a holder, if simple and (>f iiuKlerate price, would be 

 much sought after by the photographic world. .\ very near 

 approach to such an ideal film-holder will l)e found in that 

 known as the " Krena," of which a short description follows. 



Hg- ' gives a complete view of the holder (the two parts 

 are here shown seixiratcly), ready to \k filled to any camera. 

 It consists of two parts: the magazine (M) and the receiver 

 (r), each of these ixtrts lx;ing alxiut half as thick again as 

 an ordinary dark slide. The exix>sure is made in precisely the 

 s;inie way as with an ordinary ilark slide, namely, by inserting 

 the m;iga/ine in ihe slide rails of the camera, and by wilhdrawing, 

 and subsequently replacing, the shutter of the muga/ine. 



The film changing is brought alMuit simply by folding the 

 magazine and receiver together until they interlock, draw- 

 ing out the two shutters, pressing a change button to one side, 

 and pushing the shutters back again. 



The ex|)<iseil films, stored in the receiver, may then be 

 removerl for ilevelnnmcnl one by one, or as a complete pack, just 

 as ihe operator desires. 



.An automatic counter upon the back of the magazine shows 

 at a gkance how many pictures have been taken. 



The iK'Culiarily of these films is that their edges are notched, 

 and in their packing an alternnte sequence is maintained a» 

 regards the [xisilion of these notches. 



