November, 1905.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



265 



and since, as already mentioned, the breeze would then 

 be descending from above, the theorists maintained that 

 everything; was favourable for the conveyance of the 

 hypothetical germs to the bronchial apparatus of a 

 susceptible humanity. But this method of inducing 

 influenza is something similar to the process of burning 

 down a house in order to- procure roast pig. Influenza 

 germs may, unfortunately, be sown without such a 

 display of molecular energy as occurred at Krakatoa, 

 and volcanoes therefore played the part of scapegoat 

 during but a short time. Pumice stone as a suggested 

 source of influenza has, notwithstanding the recent 

 volcanic purturbations, therefore, been abandoned. 



Now the great objection to all these theories which 

 demonstrate how the influenza is wafted about by the 

 breezes is found in the fact that people in isolated posi- 

 tions escape the scourge. For instance, lighthouse- 

 keepers, the inhabitants of certain islands, and people 

 on board ships that do not touch land during lengthened 

 periods are not attacked, which they would hardly fail 

 to be were the influenza floating about in the air 

 promiscuously. Prisoners are, as a body, remarkably 

 free from visitations of the epidemic, and serve as a 

 modern instance to disprove the assertion that the 

 weather is at fault. From this point of view it would 

 appear that the best method by which to escape 

 influenza is to break one of the laws of one's country 

 and so secure a moderate period of solitary and isolated 

 confinement. 



What seems clear is that the influenza travels from 

 place to place much more quickly than was the case in 

 former years, so that an outbreak say, in Buda Pesth, 

 rapidly journeys to London. As facilities of travel have 

 increased by rail, road, and river, so have the 

 peregrinations of the epidemic been correspondingly 

 accelerated. Investigations indicate very unmistakably 

 that where the stream of travelling humanity is greatest 

 there also is influenza most easily disseminated. It is 

 near the towns that microbes, bacilli, and other ob- 

 jectionable things have their birth, and although the 

 state of the atmosphere may at times be favourable for 

 their transportation, long journeys through the air are 

 fatal to them, for the sun and the wind rob them of 

 their venom. " No climate in the world," said King 

 Charles, " invites a man to walk abroad so many days 

 in the year as the climate of England," and despite 

 the popular impression concerning influenza and the 

 weather, a walk along some country road, or over some 

 wind-filled moor or common is, after all, the surest way 

 to reduce the proportions of the doctor's bill. 



As already remarked, different types of weather are 

 associated with anticyclonic or cyclonic conditions, 

 and as regards the latter class of atmospheric vortices, 

 it is possible to trace the track or route they pursue as 

 they journey across the country, the history of their 

 travels being nowadays recorded in the meteorological 

 weather charts. Commonly these storms cross the 

 British Isles in a north-easterly direction, a favourite 

 line of travel being by way of the Caledonian Canal. 

 Now the path taken by the influenza as it passes from 

 town to town bears no sort of relation to the track of 

 the cyclones, which are the chief breeders of damp, 

 cold, windy and rainy weather, and a contemplation of 

 this fact gives no colour to the notion that influenza 

 flies as an arrow by day on the wings of the wind. It 

 is, indeed, not in protecting one's self from the health- 

 giving winds that influenza is to be averted, but rather 

 by a frequent overhauling of the dust-bin, and by 

 taking, as often as possible, a course of sun-baths. 



Abnormal FolioLge of 

 Sycamore Seedling. 



By Graham Bott, I-'.L.S. 

 The accompanying illustration (Fig. i) shows a rare 

 abnormal growth of the first pair of foliage leaves of a 

 Sycamore seedling. It will be noticed that complete 

 fusion of the petioles has taken place, and that this 

 fusion has extended tO' the leaves themselves along the 

 lower tvvo^thirds of their margins, thus forming twin 

 leaves. When compared with a normal seedling (Fig. 

 :), the anomalous condition is strikingly noticeable ; 

 and, since growth proceeds from the angle formed by 

 llie leaf-stalks, it is interesting to speculate as to what 

 would have happened in the abnormal form, with re- 

 ference to further development, had growth been 





Fig. I.— A Sycamore Seedling showing twin leaves (natural size). 



allowed to continue ; axillary orientation having been 

 arrested by the union referred to above. 



It is, of course, recognised that several plants ex- 

 hibit cohesion of the margins of their leaves as a fixed 

 character, and, according to the degree of union, desig- 

 nated by various terms. But it may not be quite so 

 familiar that many leaves of the same plant show in- 

 teresting transitional conditions from the simple form 

 through variously lobed (connate), up to the completely- 

 divided compound leaf, such as may be found on the 

 Blackberry {Riibus fruticosus) and Cinquefoil {Poienlilla 

 reptam). Partial union is observed readily, also, be- 

 tween the terminal and one of the lateral leaflets of the 

 Ash {Fraximis excelsior). And a similar fusion of the 

 leaflets of the Scarlet Bean {Phaseohis) occasionally 

 occurs, thus transforming the compound leaf into a 

 simple one. 



However, those instances are considered as reversion 

 to type, and it is strong presumptive evidence of the 

 evolution of the compound leaf from a simple form. 



