July 25, 1889] 



NATURE 



297 



The Circulation of the Atmosphere over the Equator. 



Absence from home has prevented my seeing Mr. Foulger's 

 letter on this subject till to-day. 



The observations on the upper winds over the doldrums, which 

 I have described in Nature, were taken in about 5° N. latitude 

 and 28° W. longitude, and the whole section of the trades and 

 doldrums lay in a line drawn from St. Vincent to Rio Janeiro. 



When I stated that "low clouds from south-east flew over the 

 north-east trade up to 15° N.," I meant to say that while the 

 surface-wind from the doldrum to 15° N. was the north-east 

 trade, the low or middle layers of cloud moved from south-east, 

 all along the line of the section above noted. 



Unfortunately I am unable at present to give a general scheme 

 of the circulation of the atmosphere, though I have worked at 

 the subject for years ; and my recent observations in the Andes, 

 from Peru to Cape Horn, throw much new light on the question. 



What we do know is that the surface trades either die out at 

 the doldrums, or unite into one moderate east current ; that the 

 low and middle currents over the doldrums are very variable, but 

 that the wind at these low and middle levels — say 20co-20,coo 

 feet— come usually from the south-east over the north-east trade, 

 and from the north-east over the south-east trade ; and that the 

 highest currents— over 20,000 feet— move from east over the 

 doldrums, from south-west over the north-east trade, and from 

 north-west over the south-east trade. We also know that the 

 high-level south-west and north-west winds near the equator 

 gradually descend to the earth's surface about 30° N. and 30° S. 

 respectively. 



What we do not know is the relation of the south-east low 

 and middle current over the north-east trade to the south-east 

 trade on the other side of the equator, nor have we yet dis- 

 covered what becomes of this middle current in the northern 

 hemisphere. In like manner the origin and ultimate destination 

 of the middle north- east current over the south-east trade is 

 equally a matter for future research. 



Of course, all meteorology turns round the general circulation 

 of the air through the heating of the equatorial regions, but 

 what I maintain is that the simple scheme which assumes 

 nothing but an upward current over the doldrums and a return 

 current towards each Pole is not confirmed by observation. The 

 reality is more complex, for the centre of the high doldrum cur- 

 rent is from the east, but diverges at the edges from south-west 

 and north-west. 



The discovery of the true nature of the general circulation of 

 the atmosphere from the equator to the Pole — apart from any 

 theoretical considerations—is a matter of so much importance for 

 the future of meteorology, that I hope all future travellers across 

 the equator will note carefully the direction of the clouds in low 

 latitudes. I know this is somewhat difficult on board ship for 

 want of a steady point of reference; but those whose zeal prompts 

 them to look out between 5 and 6 in the morning, and from 

 6 to 7 in the evening, will usually find the moon, or some bright 

 star, by means of which the direction of the cloud-motion can 

 be accurately determined. Above all things, the relative, and if 

 possible the actual, level must be carefully noted ; and the obser- 

 vations should not be recorded as we so often see— wind north- 

 east, clouds south-west— without any indication as to whether the 

 south-west current is at a low, middle, or high level. 



Ralph Abercromby. 

 21 Chapel Street, London, July 22. 



Changed Environment. 



It is generally known that the English sparrows were intro- 

 duced into the United States on the supposition that they were 

 insect feeders, and would protect our trees from the canker- 

 worm. For the first time in my remembrance, I have seen one 

 attack a caterpillar this summer. Their usual food appears to 

 be the seeds found in horse-manure on the streets. They are 

 now universally conceded to be an immitigated nuisance, not 

 doing their assigned work, and preventing others from doing it. 

 They usurp the place of the more charming native birds, the 

 blue-bird, the wren, and the Baltimore oriole, once common in 

 our cities. Still, we have to confess that the sparrows are 

 interesting little creatures, aggressive and pugnacious. 



I was lately t"ld of a circumstance, which I can myself now 

 confirm. An " American robin" was seen watching a beetle, 

 known here as the " June bug,'' that had just emerged from the 

 ground. He tossed him about with his bill, and was closely 



watched by a sparrow who had alighted about a foot away. 

 Seeing the latter, the robin at once attacked him, when the 

 sparrow made a dive between his legs, seized the beetle and 

 flew away. A robin rarely hunts for earth-worms, of which 

 robins are especially fond, without being followed by one or 

 more sparrows. These often get the worm for which the larger 

 but less agile bird has laboured. 



Another matter suggests itself to me. Mr. Wallace in his new 

 and delightful book on " Darwinism," which reawakens one's 

 old enthusiasm, says that many plants live "not where they 

 must, but where they can." The natural habitat does not always 

 appear to be the best. Thus, Lobelia rai-dinalis, so common 

 in our Rhode Island woods, is always found on the brink of 

 running streams, or where these have been, or near water. It 

 is in such sense aquatic. But, removed to a garden, it will grow 

 vigorously and multiply astonishingly exposed to full sunlight 

 and in ordinary loam. Indeed, the plants prefer to escape from 

 the beds into the gravelly paths. They will overrun a garden. 



Asta- Novcc-A)igli(C is not one of our most abundant asters, 

 but in a garden it will crowd out all else. The seedlings spring 

 up even in the dry soil loved by Plantago major. Viola pcdata, 

 which grows naturally in sand, will flourish and increase in size 

 by cultivation, becoming as handsome as a pansy. Corydalis 

 glauca grows in nature on hot exposed rocks and cliffs; it will 

 grow larger and better, and set seed abundantly, in rich loam. 



I could multiply instances of such changed environment 

 where the result was beneficial. W. Whitman Bailey. 



Brown University, Providence, Rhode Island, U.S.A., 

 July 2. 



Lamarck versus Weismann. 



I SHOULD like to call the attention of those interested in 

 organic evolution to a remarkable passage in Mr. Wallace's 

 recent volume on " Darwinism." This work is throughout an 

 argument in defence of Darwinian principles, in their original 

 unmodified form as stated in the " Origin of Species," in oppo- 

 shion to all recent criticism or development of those principles. 

 And yet on p. 129 the author publishes the following passage : — 

 " Now the eyes of these fish (Pleuronectidse) are curiously dis- 

 torted in order that both eyes may be on the upper side, where 

 alone they would be of any use. It was objected by Mr. 

 Mivart that a sudden transformation of the eye from one side to, 

 the other was inconceivable, while if the transit were gradual, 

 the first step could be of no use since this would not remove the 

 eye from the lower side. But, as Mr. Darwin shows by refer- 

 ence to the researches of Malm and others, the young of these 

 fish are quite symmetrical, and during their growth exhibit to us 

 the whole process of change. This begins by the fish (owing to 

 the increasing depth of the body) being unable to maintain the 

 vertical position, so that it falls on one side. It then twists the 

 lower eye as much as possible towards the upper side ; and the 

 whole bony structure of the head being at this time soft and 

 flexible, the constant repefiiion of this effort causes the eye gra- 

 dually to move round the head till it comes to the upper side. Now 

 if we suppose this process, which in the young is completed in a 

 few days or weeks, to have been spread over thousands of gene- 

 rations during the development of these fish, those usually sur- 

 viving whose eyes retained more and more of the position into 

 which the young fish tried to txvist them, the change becomes 

 intelligible." 



A Lamarckian could accept the above passage almost without 

 altering a word. The words I have italicized describe with 

 absolute precision the muscular eff'ort of the fish as the active 

 cause, both of the individual and the ancestral metamorphosis. 

 And yet, in chap, xiv., Mr. Wallace expresses his acceptance of 

 Weismann's dogma of the non-inheritance of acquired characters 

 with the words, "We cannot therefore accept any arguments 

 against the agency of natural selection which are based upon 

 the opposite and equally unproved theory that acquired 

 characters are inherited ; and as this applies to the whole school 

 of what may be termed Neo-Lamarckians, their speculations cease 

 to have any weight." J. T. Cunningham. 



July 19. 



Bored Stones in Boulder Clays, 



Stones bored by Pholas and Saxicava are by no means rare 

 .n the shelly " Basement clay " of East Yorkshire, and I have 

 occasionally found examples in which the shells remained in the 



