202 



NATURE 



[July 2, 1891 



constellations used by people earlier than the Greeks, but 

 still much is to be hoped from the study of the Babylonian 

 records. In these we have a snail being drawn along by 

 the tail of a snake or dragon. It is quite possible that 

 we may have there the origin of our constellation Draco, 

 which is the northern constellation, and it is quite possible 

 that this snail may indicate that the stars in it moved 

 with very great slowness. But it is impossible at present 

 to co-ordinate these different fancies together. 



A very important paper has recently been published 

 by Mr. Le Page Renouf suggesting that before the year 

 1500 B.C. the Egyptians really had an idea of meridional 

 observations. These observations are recorded in several 

 manuscripts found in tombs ; they seem to have been 

 given as a sort of charm to the people who were buried 

 in order to enable them to get through the difficulties of 

 the way in the nether world. 



The hieroglyphs state that a particular star of a parti- 

 cular Egyptian constellation is seen at a particular hour 

 of the night ; we have twelve lines representing the twelve 

 hours of the night, and it is stated that we have in these 

 vertical lines the equivalent of the lines in our transit 

 instruments, and that the reference "in the middle," 

 " over the right eye," " over the right shoulder," or " over 

 the left ear," as the case may be, is simply a reference to 

 the position of the star. 



If this should be confirmed, one of the remarkable 

 things about the inquiry will be that the Egyptians did 

 not hesitate to make a constellation cover very nearly 90^. 

 In those days evidently they wished to have as few con- 

 stellations including as many stars as possible, in order 

 perhaps that things might be more easily remembered. 



When the zodiac of Denderah was mentioned, I pointed 

 out the constellation of the Hippopotamus very near the 

 north pole. This constellation is referred to in the records 

 in question. 



Such then are some of the ideas which are suggested 

 by the recent work of the Egyptologists. You see, I 

 trust, that it is important that this work should be con- 

 tinued as closely associated as possible with astronomical 

 ideas, because, merely taking a very small part of the 

 area of which they have begun the consideration, we have 

 come to the conclusion that, dealing with the temples 

 alone, there seems a very high probability that 3000, and 

 possibly 4000 B.C. the Egyptians had among them men 

 with some knowledge of astronomy, and that 6000 years 

 ago the course of the sun through the year was practically 

 very well known, and methods had been invented by 

 means of which it might in time be better known, and 

 that not very long after that they not only considered 

 questions relating to the sun, but began to take up other 

 questions relating to the positions and the movements of 

 the stars. It is quite probable that 1500 years B.C. 

 at least they had an idea of meridional observations. 

 If this be so, and if more and more can be proved, I 

 think you will agree that, as I said before, astronomy 

 will have a slight opportunity of repaying some of the 

 great debt which she owes to the other sciences. 



J. Norman Lockyer. 



THE LATER LARVAL DEVELOPMENT OF 

 AMPHIOXUS. 



THE memoir by Mr. Arthur Willey, B.Sc, of University 

 College, London, on this subject, in the Quart. Journ. 

 Microsc. Science, March 1891, deserves more than a 

 passing notice. It is one of the most important contribu- 

 tions which have been made to a knowledge of this very 

 interesting animal. In the summer of 1889, Mr. Willey 

 was sent by Prof. Ray Lankester with the aid of a Govern- 

 ment grant to collect the larvae and embryos of Amphioxus 

 at Faro, near Messina. He returned with a large series, 

 and in the winter 1889-90 workei out in the laboratory of 



NO. I 131, VOL. 44] 



University College, chiefly by means of sections, the 

 history of the formation of the atrial cavity in this animal. 

 In a paper published jointly by Prof. Lankester and Mr. 

 Willey {Quart. Jourti. Alter. Set., August 1890), it was 

 shown that the atrial cavity does not form, as supposed by 

 Kowalewsky and by Rolph, as the result of a down-growth 

 of lateral epipleura ; but that it forms as a longitudinal 

 groove which sinks inwards along the ventral surface, 

 becoming floored in by a small horizontal growth on each 

 side corresponding merely to that portion of the adult 

 animal's ventral surface which lies between the two 

 metapleura. The groove, now become a narrow tube, 

 expands right and left, until it acquires the proportions of 

 the adult atrial chamber. 



• The preserved material brought home by Mr. Willey 

 in 1889 did not enable the observers to determine the 

 mode of origin of the second row of gill-slits. Stages 

 were noted in which there were as many as fourteen gill- 

 slits of the first series (which are placed anteriorly on the 

 animal's right side), and stages were observed, of no 

 greater size, in which two rows of gill-slits were present — 

 one series on the right side and one on the left side of the 

 pharynx ; whilst the mouth, which in the specimens with 

 a single series was completely lateral (on the left side), 

 had now taken up a median position. 



Mr. Willey again visited Faro in the summer of 1890, 

 for the purpose of determining, by the study of living 

 transparent larvae, exactly the mode of origin of the second 

 row of slits, and the steps in the "symmetrization" of the 

 larva. The brief account and few unconvincing figures 

 given by Kowalewsky, in 1866, in relation to this matter 

 had not commanded general confidence, although it was 

 felt that so accurate and accomplished an observer could 

 not have been completely mistaken. Balfour had said, 

 in reference to Kowalewsky's observations on this matter, 

 that he was " tempted to suppose that his observations 

 were made on pathological specimens." 



Mr. Willey completely and most successfully accom- 

 plished the object which he set before himself in his 

 second visit to Faro, and the results obtained are given 

 in the paper under notice, illustrated by three folding- 

 plates. He confirmed the main feature of Kowalewsky's 

 observations, viz. that the first row of gill-slits, after 

 having (so far as the first eight are concerned) taken up 

 a position on the right side of the pharynx, rotate down- 

 wards across the median ventral line, and rise up into 

 position on the' left side, whilst, simultaneously, a new 

 series appears on the right side, not one by one, but as 

 many as six being formed at approximately the same 

 moment. Mr. Willey corrects Kowalewsky's brief ac- 

 count in one or two numerical details, and adds some 

 very important facts, which are quite new. He shows : 

 {a) that the anteriormost slit of the primary series closes 

 up and disappears during the process of rotation ; {b) that 

 some of the hinder slits of this series, which are not far 

 advanced when the rotation begins (there being usually 

 fourteen, of which the last six are very small, and lie in 

 the median ventral line), also close up ; so that, when 

 the rotation is complete, and the second series of gill-slits 

 has advanced in development to the number of eight, a 

 " critical phase " is reached in which there are only eight 

 gill-slits on each side of the pharynx, all fairly well 

 developed. From this time forward new gill-slits are 

 formed on each side behind the last formed, and continue 

 to increase in number so long as growth continues, which 

 appears to be as long as the Amphioxus hves. 



But the most important discovery made by Mr. Willey 

 is as to the origin of the endostyle, a structure which has 

 great importance from the fact that it can be clearly 

 identified, on account of its minute histological structure, 

 with the endostyle of the Ascidians. 



In the anterior region of the buccal cavity, previous 

 observers have described in very young Amphioxus larvae 

 (with only one gill-slit) an elongated gland; " the club- 



