I50 



NA TURE 



[December 15, 1892 



She was even unable to trace a circle, except as part of a man 

 (the head). 



In a paper presented at the London meeting of the International 

 Congress for Experimental Psychology last August, I insisted 

 that voluntary movements are possible in the child only after 

 a great variety of motor "elements" have become available 

 through great diffusion and mass in involuntary (imitative) 

 reactions. 1 The above phenomenon, thus explained, serves to 

 illustrate the broader position. 



As there is no literature on this subject, the question of 

 "tracery-imitation" has not even been put before, to my 

 knowledge, I should be glad to have opinions upon it. It is 

 evident that if one hold the other theory of the visual apprehen- 

 sion of figure, i.e. that it is given by sight apart from sensations, 

 of eye-m jvement, he could still hold the explanation which I 

 have offered above, by substituting for the series of eye-move- 

 ment sensations, a, a\, a^, &c., a series of visual sensations, 

 V, z)\ V-, &c. J. Mark Baldwin. 



Difficulties of Pliocene Geology. 



Considering the very great importance which the later 

 tertiary beds must occupy in all speculations about the origin 

 of man and the present geographical distribution of plants and 

 animals, it is unfortunate that they should have attracted so little 

 attention among English geologists. 



The fact is perhaps not unnatural when we consider how very 

 scantily they are represented in this country ; the Norwich Crag 

 being virtually the only bed where remains of pliocene land 

 animals have occurred. The Norwich Crag is itself a very 

 puzzling bed, where marine remains and land remains are found 

 mixed together, the whole having been reassorted, and I do not 

 know of a single pliocene land surface remaining intact in 

 Britain. The so-called forest-bed can no longer be classed as 

 pliocene, but is clearly of pleistocene age. A real mark of the 

 true pliocene horizon in Europe is the occurrence of the mas- 

 todon and its associated fauna. 



If we are to use the mastodon as a test we shall have to 

 travel southward as far as Auvergne, if we are to find a pliocene 

 land surface zu situ. Unfortunately Auvergne is a very dis- 

 located and broken country, and the sequence of the later 

 deposits is very hard to make out, and I much question whether 

 it be possible to find sections showing the true reading of the 

 beds in question nearer than Florence. 



I am writing in the hope that I may persuade Dr. Forsyth 

 Major, who knows the valley of the Arno so well, to communi- 

 cate to Nature some account of the results arrived at by th? 

 Italian geologists. 



At present the question is one of great perplexity. Let me 

 refer to two points. First, How comes it that in no part of the 

 world, so far as I know, has a single fragment of an undoubted 

 pliocene beast been found in a cave ? The carnivora of pliocene 

 times must have frequented caves just as much as the bears 

 and hyenas of pleistocene times, yet how comes it that we 

 can nowhere find any tertiary remains in any cavern ? It 

 will not do to appeal to denudation, for if there be deposits any- 

 where protected from denudation it is those in caves. Can it be 

 that every mountain chain where limestone rocks occur is 

 younger than pliocene times ? 



Again, we know that in America, both north and south, the 

 mastodon survived to the end of the Pleistocene age, and lived 

 alongside of the mammoth and the Columbian elephant. In 

 Europe there is very great doubt whether the mastodon and 

 any form of elephant were ever contemporaries. No doubt the 

 teeth of the mastodon have been found with those of the 

 elephant in the Crags, but the Crags have been so rearranged 

 that it is impossible to draw any safe conclusions from them. 

 It is at all events extraordinary that, according to the French 

 geologists, the two beasts have never been found together in 

 France.. I believe the same conclusion has been arrived at by 

 the Italian geologists; but upon this point there is some uncer- 

 tainty, and it would be very interesting to have the opinion of 

 so competent an authority as Dr. Forsyth Major upon the 

 point. It is one of importance, for upon it depends largely the 

 question of whether there was a continuity in Europe between 

 the pliocene and pleistocene land, or whether, as I am disposed 

 to believe, there was a break between the two involving 

 perhaps a violent revolution. There are other interesting 



I An abstract of the paper is to be found in Science, November i8, 1892, 

 and also in the Proceedings of the Congress. 



NO. 1207, VOL. 47] 



questions involved in the issue I have raised, upon which you 

 may possibly permit me to write on another occasion. Mean- 

 while the burden of my present letter is to point out how 

 httle we really know about the pliocene land, and how useful 

 U would be to know more. Henry H. Howorth. 



The Athenaeum Club, Decemberj5. 



Meteors, 

 A FINE meteoric shower was observed here on the night of 

 November 23, from yh. 30m. to 12b. 30m., when the obser- 

 vations were interrupted by cloud. 1 The meteors were evi- 

 dently " Bielids," the radiant at 8,30 being near a point, R. A., 

 ih 20m. ; Dec, 40° 30'. The radiant, however, was not 

 well defined, its area being at least 4° in diameter. For a 

 single observer, in a position which commanded only about one- 

 sixth of the visible hemisphere, the meteors numbered about six 

 a minute, which would indicate at least seventy-five a minute 

 for the entire sky, exhaustively observed. 



At ten o'clock two observers, standing back to back in an 

 open space, counted 104 meteors in five minutes ; the position 

 of the radiant being then, R.A., ih. 30m. ; Dec, 41° 30' 

 —very near Upsilon Andromedse. At this time the radiant 

 seemed to be rather more definite than earlier, and several 

 nearly stationary meteors determined the place with reasonable 

 precision. 



An hour later a similar count by the same two observers gave 

 100 meteors in four minutes and a half, and the radiant was 

 determined at R.A., ih. 4003., Dec, 40°. The rate of fre- 

 quency continued at)out the same until the sky clouded up an 

 hour later, and must, I think, be estimated as high as from 80 

 to 100 a minute for the whole number that might have been 

 seen by a sufficient corps of observers. This would foot up from 

 24,000 to 30,000 for the five hours. 



I am not quite certain whether the apparent change in the 

 position of the radiant is, or is not, real; but a motion very 

 similar in amount and direction is given by Denza in his obser- 

 vations of the meteoric shower of 1885 (see Nature, vol. xxxiii. 

 page 151). 



Comet "/" (Holmes's) was about io° west and 4° south of the 

 mean radiant at R. A, oh. 40m., Dec, 360° 45'. It was barely 

 visible to the naked eye. 



Most of the meteors were very small, not exceeding the fifth 

 magnitude ; hut a few, perhaps one in ten, were above the 

 second, and in the course of the night four were seen which 

 rivalled or surpassed Jupiter. The brighter ones left bluish 

 trains, which remained visible for three or four seconds. The 

 smaller ones often came in " flights" of three or four together, 

 and fully half the paths were more or less curved and wavy from 

 the resistance of the air. 



It is worthy of notice that the heliocentric longitude of the 

 earth at the time of the shower was about 62°, instead of 65° 

 which was the longitude of the descending node of Hiela's orbit 

 at the last appearance of the comet in 1852, and was the longi- 

 tude of the earth at the time of the showers of 1872 and 1885. 

 The fact suggests the inquiry whether perturbations since 1885 

 will fairly account for such a recession of the node. 



It is Obvious also that if the meteoric swarms encountered by 

 the earth in 1872 and 1885 were really moving in the orbit of 

 Biela's comet (which at its last appearance had a period of 6*& 

 years), then the swarm encountered the other night, just seven 

 years later, must have been an entirely different one — unless 

 indeed the perturbations since 1885 can account for a retardation 

 of nearly five months. 



Last night was for the most part overcast, but a watch of 

 fifteen minutes through occasional openings in the clouds showed 

 only one or two possible Bielids. Evidently the shower was 

 not continuing with any intensity. C. A. Young. 



Princeton, N.J., U.S., November 25. 



Comparative Sunshine. 

 After explaining that by "sunshine" I intend that which 

 K/^w/af fall upon the earth if there were no atmospheric obstruc- 

 tion, one must first notice the very elementary truth that the 

 amount of such sunshine at any assumed time and place is in 

 l)roportion to the altitude of the sun at noon, and also the 



_ I Our "Eastern standard time" is just five hours slower than Greenwich 

 time. 



