222 



NATURE 



\yan. 1 8, 1872 



arms were found to commence as a series of ciliated 

 tentacles placed around the mouth, and as nearly as 

 possible identical with the lophophor of such a Polyzoon 

 as PcdiccUhia. At 'first but six of these tentacles are seen ; 

 these increase in number, whilst the lophophor takes on 

 its horse-shoe shape ; and finally by the development of 

 the free ends of the two sides of the horse-shoe the great 

 IJrachiopodian arms are produced. This is very interest- 

 ing, and confirms i!/n''iV7 notions. At the same time ive 

 must dissent from the stress which Mr. Morse lays on the 

 affinities of structure of Brachiopoda and Polyzoa, in 

 so far as he wishes to separate these two widely from 

 the Mollusca, and join them to a group which he calls 

 Vermes. The Vermes have never been accurately defined, 

 and arc in fact at present, as Carl Gegenbaur (whom Mr. 

 Morse cites) fully admits, one of those classficatory 

 lumber-rooms, which are so convenient from time to time 

 in the progress of zoological science. Whilst we fully 

 admit the close affinities of the Polyzoa and the Brachio- 

 poda — now long recognised by all zoologists— -we cannot 

 overlook the very strong affinities of these to the true 

 Mollusca. Even a hasty study of the embryology of the 

 Mollusca is sufficient to bring under one's eyes larval 

 forms of various classes bearing many of the charac- 

 teristics of the Polyzoa on the one hand, and of certain 

 Vermes on the other. The early condition of the gill- 

 plates in some Lamellibranchs is only to be compared to 

 the tentacula of the Molluscoidan lophophor, though pre- 

 senting so large a shifting in some relations. Rather 

 than detach the Molluscoida (with regard to the Tunicata 

 there are a variety of new facts and considerations which 

 require long discussion) from the Mollusca to place them 

 in the lumber-room Vermes — we should prefer to put the 

 whole of the Mollusca along with them there — a proceed- 

 ing at present useless, but which would express a truth 

 which Mr. Morse does not seem to admit, though it is 

 indicated by Gegenbaur, and accepted also by Huxley, 

 namely, that there are close genetic ties between the group 

 Mollusca (including Molluscoida), and certain so-called 

 Vermes, such as the Turbellaria, Archi-annelida, &c. 



In a paper published prior to this, Mr. Morse has 

 spoken of the Brachiopoda as a division of Annelida, on 

 the ground of certain resemblances between Lingula and 

 Annelids. We are not sure whether Mr. Morse adheres 

 to this startling proposition, or whether it was due to the 

 intensity of the impressions produced by his study of 

 living Lingute, which must have been exceedingly in- 

 teresting. By the way, we may mention that Semper has 

 also studied living Lingula. That there is a fundamental 

 community of organisation between Lingula and Anne- 

 lids we are, as stated above, not indisposed to believe, but 

 that this can be expressed advantageously by making the 

 Brachiopoda a division of Annelida, or that such a classi- 

 fication would be anything more than reactionary exagge- 

 ration, we cannot for a moment suppose. Mr. Morse 

 attaches importance in this regard to the set;i; of Lingula, 

 and equal or perhaps more importance to the red colour 

 of the blood. The discovery of red-coloured blood in 

 Lingula is interesting, because in all probability it is due, 

 as in vertebrates and all other causes where it is really red, 

 to the presence of liEemoglobin, and is another instance 

 of the exceptional appearance of this chemical principle 

 in the blood of an animal whose nearest congeners do not 



possess it. We should be very glad of confirmation with 

 the spectroscope of the supposed existence of h;Lmoglobin 

 in the blood of Lingula. But how can Mr. Morse sup- 

 pose that this red blood, or haemoglobin-bearing blood, is 

 a character of the slightest classificatory importance ? A 

 great number of Annelids do not possess the vascular 

 system at all, which in others carries this red blood ; in 

 some the fluid in that vascular system is coloured green 

 by chlorocruorin, in others the haemoglobin is present 

 in the perivisceral fluid, which is in most Annelida colour- 

 less. Certain Mollusca have blood coloured red by 

 hemoglobin (Planorbis) as deeply and brightly as that of 

 any lob-worm, so again have some Crustacea and Insect 

 larva;. The presence or absence therefore of hemo- 

 globin in the blood of Lingula is a matter of complete in- 

 difference as far as the relations of that animal to the 

 Annelida are concerned. 



We are much interested by a reference in Mr. Morse's 

 paper on Terebratulina to some observations which he 

 has made on the development of Lingula, observations 

 which we hope before long to see published. From these 

 he states that he is led to believe that the supposed 

 Discina larva figured by Fritz Muller might equally as 

 well be that of a Lingula. Some further information about 

 this remarkable larval form will be very welcome. 



Mr. Morse apologises for the undetailed character of 

 his drawings, and for the absence of information in his 

 paper upon the development of Terebratulina a'> ovo — 

 a great desideratum — by the fact that when he went to 

 Eastport to study the development of Terebratulina he 

 had a microscope with him which he found to be utterly 

 inadequate to the purpose. Since this is an error which 

 is easily remedied, we trust that Mr. Morse will soon 

 return to the attack, if he has not yet already done so, 

 duly armed. 



E. R.AY Lank ESTER 



LETTERS TO THE EDITOR 



[The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 communications. ] 



The Solar Eclipse 



It does not happen more than once in a liTetime to see such 

 a glotious and magnificent sight as that from which I have just 

 returned ; that is, the total eclipse of the suu. I have seen many 

 eclipses befure, but never anything to equal this. I was engaged 

 to go with the Morgans to the top of the hill to see it. Got up 

 at si.v, and found it a lovely morning ; rode up to Morgan's, 

 about half a mile, carrying with me glasses, smol;ed glass, and 

 sun hat. Got there before seven, and found eclipse already 

 begun. Got our two mirrors and watched the h ile in the suti 

 grow bigger and bigger. It began from the top, and we all went 

 off to the highest point on the hill, from whence we could see 

 all Ooly and the mountains round. When the eclipse got so far, 

 the cold on the mountain grew much greater, the grass was so 

 wet that no one's boots kept it out, the feet and hands grew cold, 

 and with your back to the sun the light over the country was 

 like twilight, or the earliest dawn. Gradually the lower streak 

 got thinner and thinner, until at last there shone a light like the 

 famous lime-light, and in a moment or two that went out and the 

 sun was totally concealed ; many stars were visible, the whole 

 country looked dark — that is, half dark, like mionlight — th- 

 crows sfopped cawing, and for two minutes and a half the total 

 eclipse lasted, a sight I shall never foiget, and then the lime-light 

 again appeared at the bottom rim of the sun, and gradually more 

 and more of him appeared, the crows began again at once, and the 



