*

The pit for the ligamentum teres is almost constantly absent, while in man, Gibbons, and the Chimpanzee, it is constantly present. The Gorilla alone sometimes shares with the Orang the condition of having no such pit.

The Orang has the shortest shin-bone, compared with the upper arm-bone, and the longest foot compared with the leg, in the whole order. It has the relatively shortest and most imperfect hallux of any Primate, while in no other Ape or Half-Ape does the length of the second toe so closely approach that of the forefinger of the same individual.

Estimated by the skeleton only, the Orang cannot be said to approximate to man in any supreme degree, although, as may be remembered, several points have been mentioned in which it is more human than in any other latisternal ape.

The Gorilla and Chimpanzee have been seen to show many approximations to man as regards the skeleton. In some respects one species has been found to be the more man-like; in other points the other species has been so found.

We have found that the Gibbons, one or other of them, exhibit various skeletal characters more human than those presented by any other members of the order. Finally, we have seen that even some of the Half-Apes present most remarkable resemblances to man. The teaching, then, of the skeleton, as also of the other parts we have as yet reviewed, seems to be that resemblance to man is shared in different and not very unequal degrees by divers species of the order, rather than that any one kind is plainly and unquestionably much more human than any of the others.

Affinities seem rather to radiate from man in various directions than to follow one special route. At present, however, the facts presented are not sufficient to warrant the expression of a confident judgment. In order to arrive at such a judgment it will be necessary to survey the other organs of the body; and then, summarizing the results, we shall have material sufficient to examine the third question proposed, namely, the bearing of the facts upon the theory of evolution as applied to

man.

(To be continued.)

• This is a ligament which holds the thigh-bone in its place, passing as it does, like a round cord, from the head of the thigh-bone to the inside of the socket of the haunch-bone, into which the thigh-bone fits.

EXPLANATION OF PLATE XCV.

FIG. 1. The Gorilla (Troglodytes gorilla).

2. Skull of the Gorilla vertically and antero-posteriorly bisected, to show the great sagittal crest (s) rising above the brain cavity, and the supra-orbital crest (o) above the orbit.

3. The Squirrel Monkey (chrysothrix sciurea).

4. The Potto (Perodicticus Potto), showing the rudimentary condition of the index finger.

5. The Angwántibo (Arctocebus calabarensis).

6. The Tarsier (Tarsius spectrum), showing the foot at its maximum of elongation, relatively, in the whole order Primates.

7. The Aye-Aye (Cheiromys madagascariensis).

139

THE LOST COMET AND ITS METEOR-TRAIN.

BY RICHARD A. PROCTOR, B.A. (CAMBRIDGE). HONORARY SECRETARY OF THE ROYAL ASTRONOMICAL SOCIETY; AUTHOR OF "OTHER WORLDS THAN OURS," " "THE SUN," &c.

THE

HE meteor-shower which occurred on November 27 last, and the circumstances connected with that event, have not only attracted a fresh interest to the subject of meteoric astronomy, but have afforded important evidence respecting the connection which undoubtedly exists between meteors and comets. I propose in this paper to consider more particularly the events referred to; for, although I have not hitherto in these pages dealt with the progress of cometic and meteoric astronomy, yet it is known to the majority of my readers that elsewhere this subject has been somewhat fully discussed by me.

It has been shown by the labours of Schiaparelli, Adams, Peters, Tempel, and other astronomers, that the meteors of November 13-14 (called the Leonides) travel in the track of Tempel's comet. The meteors of August 10-11, or Perseides, have also been shown to travel in the track of a comet. Other such instances of association have been more or less fully recognised; and now the conclusion has been generally accepted, that in the train or path of comets bodies travel in scattered flights, which, if they fall on the atmosphere of the earth, appear as shooting-stars or meteors.

Until the recent shower, however, the inquiries made in this branch of research has been limited to cases of recognised meteor-systems whose orbits have been found to agree with those of comets. It was a new circumstance in the history of meteoric research when Weiss in Germany, and Alexander Herschel in England, ventured to predict a meteoric display because the earth was about to pass through the orbit of a known comet. It is true that there were some reasons for believing that meteors which had fallen in various years between November 25 and December 7 were attendants upon the comet in question-Biela's or Gambart's. But the evidence was slight, and in some respects unsatisfactory; so that it may be said that

in reality the astronomers just named had no other grounds for their anticipations than first the fact that Biela's comet was known to have recently passed the descending node of its orbit (or the place where it passes nearest to the earth's orbit), and secondly their confidence in the theory that meteors and comets are in some way associated. A prediction such as this became therefore in some sense a crucial test of this theory-not indeed that the failure of the prediction would have disproved the theory (because negative evidence counts for little in this matter), but that its fulfilment would supply the only form of positive evidence yet wanting to that theory.

I do not here enter at length on the remarkable circumstances connected with Biela's comet, because they have been elsewhere stated at considerable length, and are probably known to the majority of those who will read these lines. Let it suffice to say that the comet was one of short period, returning at mean intervals of 6.635 years; that in 1837 it was observed to be divided into two distinct comets; that it returned in 1852, and both the comets were then still in existence; that whether it returned (unchanged in general aspect) in 1858-59 or not, is unknown, because its calculated course was such as to render observation impossible; and lastly that in 1866, and again last year, it was searched for in vain with telescopes of great power.

Now it crossed the earth's path last year nearly twelve weeks before November 27, when the earth herself traversed the place at which the comet crosses her orbit. And since the meteors of November 13-14 have been seen, not merely a few months, but several years after the nodal passage of their comet, it seemed not unreasonable to expect a considerable meteoric display on or about November 27. The exact date was not indeed very accurately determined, and the reason is readily seen. I invite the reader's special attention to the point, because it has been somewhat singularly overlooked even by astronomers of great mathematical attainments. The comet itself had its place of passage readily calculated, and it might seem at first sight that whenever the earth came to that place the display should occur. But manifestly the position of the cometic orbit for November 27, when the earth crossed that orbit's node, would not be identical with the position of that orbit three months or so before, when the comet passed its node. It might then seem that this latter position was what astronomers should calculate, and as a matter of fact this is what was commonly done. We find the position of the node of the orbit for the end of November assigned as the place where the encounter of the earth with the meteoric flight was to take place. But this view is as incorrect as the former.

Those particular meteors which were travelling twelve weeks behind the head of the comet, although, speaking generally, they would follow the comet's track, would nevertheless not be found travelling in precisely the same orbit, nor would they cross the earth's orbit precisely where the comet's orbit did at the time. For they would have been subjected to perturbations differing notably in character from those which had affected the comet itself. It must be remembered that the circumstances which separated such meteors by so great a distance from the head have not taken place in a few years, in a few revolutions of the comet, or even in a few centuries. But even if we take only the last half century or so, and consider the history of those meteors during that time, it will be manifest that their perturbations have differed considerably from those which have affected their leader, so to term the comet in whose track they follow. In the course of those years the comet has made seven or eight revolutions, and so have the meteors, while Jupiter, the chief disturber of Biela's comet, has made four or five revolutions. In the course of this period the comet must have been more than once so placed as to be very considerably disturbed by Jupiter, because as a matter of fact the path of the comet passes not very far (near its aphelion) from the path of Jupiter. The same general statement is true, of course, of the meteors twelve weeks behind. Now, whenever it happened that the comet was at its nearest to Jupiter, when passing that critical portion of its orbit, the meteors twelve weeks behind were either not brought so fully under the influence of Jupiter's attraction, or if they were, they were perturbed by him in a different manner. This is manifest if we consider how enormous is the real distance corresponding to the twelve weeks or so by which the meteors are behind the comet. And again, when the meteors chanced to be at their nearest to Jupiter when passing the critical part of their orbit, the comet, twelve weeks in front, was either not brought so fully under Jupiter's influence, or was perturbed in a different way.

Now whenever a perturbation has been produced, it affects the orbit of the perturbed body. Supposing the comet and meteors moving in precisely the same orbit at a particular moment, when Jupiter is pulling the comet in a certain way and the meteors in a different way, then forthwith the comet and meteors travel in different orbits. The difference may be slight, close by the place where such perturbations are produced, but it may nevertheless appreciably affect the positions which will be occupied by the comet and meteors when severally traversing some other and distant part of their orbit (as for instance when they are at their descending node close by the earth's track). And again, although in the long run there are