Au^. I, 1872] 



NATURE 



27: 



ayaiii at \'alparaiso. The trend of the glacial scratches in San 

 Vicente remin-Js nie of a fact I have often observed in New 

 England near the sea shore, where the ylacial furrows dip to a 

 considerable extent eastward toward the deep ocean, wliile farther 

 inland tlieir trend is more regular and due north and sou'di. 



While in Talcahudno we have made very extensive collections of 

 litttu'al marine animals, so that we now have an excellent basis for 

 comparison with the results of the deep-sea diedgings, which 

 Pour, ales is going to make between thii and Juan Fernandez. I 

 shall make similar collections in Valparaiso, and in order to do 

 so in the short time allowed me I take Dr. Steindachner with me. 



I had almost forgotten to say that I have obtained un- 

 questionable evidence of the cretaceous age of the coal deposits 

 of Lota and the adjoining localities north and south, which are 

 generally supposed to bi tertiary lignites. They are overlain by 

 sandstone containing baculites. X need not adduce other evidence 

 to satisfy geologists of the correctness of my assertion. I have 

 collected myself a great many specimens of these fossils in beds 

 resting upon coal seams. L. Ag.\ssiz 



To Prof. Benj. Peirce, Superintendent U.S. Coast Survey 



ANATOMY 



The Placenta of the " Tamandua " Ant-eater 



To the last number of i\\s Anna'js dcs Scienci's NatKrdlcs M. 

 Alphonse MiUie-Edwards contributes an important paper upon 

 the structure of the placenta of the "Tamandua" ant-eater 

 (TamanJua iciraJaciy/a}— important, at all events, to those 

 who, with us, reckon the Bnita as one of the most interesting, 

 but, at the same time, spite of Dr. Gray's most elaborate but 

 somewhat intricate arrangement,*' least satisfactorily classified 

 groups of the mammalian class. 



JI. Milne-Edwards, after mentioning his countryman Lenou's 

 division of the ant-eaters proper into three genera— viz. , the 

 terrestrial lilyrmaoplia^a, and the Taniaiuhia and Cyclolliiinis 

 with arboreal habit and correlated prehensile tail, draws atten- 

 tion to the fact that as yet no opportunity has been had of 

 examining the fcetal envelopes of the great ant-eater (AI. Jiil'ala), 

 that the placenta of the two-toed genus Cydothurus is described 

 in the Lemons as a kind of concave disc, but it has not been de- 

 termined to what extent the walls of the ovum are occupied by 

 the specialised vascular tuft. 



The fcetal specimen of the Tamandua examined by M. Milne- 

 Edwards was derived from a female which had come from New 

 Grenada. The placenta is described as situated at the end of a 

 pretty long and cylindrical umbilical cord, in which the vessels 

 did not take any special course. It occupies a considerable 

 extent of the ovum, and though circular and made up of but a 

 single lobe, is of a form too convex (Irop t'onibei) to come 

 under the category of the so-called "discoidal" placenta. It 

 would be, in fact, more correct to term it a " placenta discoidale 

 envahissante. " It is not made up of single villosities, such as 

 the placenta of Pachyderms, of Camels, and of Tragulines, for 

 the vascular tufts are much crowded together, especially at the 

 central portion, so as to give the organ at this point a spongy 

 appearance. The edges are sharply defined, leaving that portion 

 of the chorion smooth which corresponds to the neck of the 

 uterus. The vascular vegetations do not, in their disposition, 

 remind one in any degree of the reticulated fold and the honey- 

 combed aspect described by Sharpey as occurring in the placenta 

 of the Pangolin. Towards the centre there appeared to be 

 debris of the uterine tissue, suggesting the existence of a 

 "decidua,"but on this point there is, unlortunately, no certainty. 

 No trace of an allantois was discovered, from which it is con- 

 cluded that this fcetal appendage must be at least greatly re- 

 duced in size. Owing to the long immersion of the animal in 

 alcoh'i', it was impossible to dissect out the lamina: of the 

 envelopes of the ovum, or the factors of the umbilical cord. The 

 internal surface of the chorion is stated to have been perfectly 

 smooth, and not to have presented any of the protuberances 

 which have been observed on that of the Unau. 



If the placenta of the Tamandua, remarks M. Milne-Ed- 

 wards in conclusion, be compared with that of some other 

 members of the groups into which the Edentata have been sub- 

 divided, we shall not fail to be struck with the considerable 

 differences which seem to exist in the structure of this organ in 



• "Revision of the Ge 

 Froc. Zool. Soc, April i j 



Liid Species of Entomophagous Edentata." 



the different members of a group considered by zoologists as 

 constituting but a single order. 



The figures given by Carus {TabuUc Anatomiam coinparativain 

 illitslraiitcs, Pars, id., PI. ix., fig. 15), of the placenta of the 

 Unau, do not, in the eyes of M. Milne-Edwards, resemble that 

 of an ant-eater, of any other kind of Edentata, or even of any 

 .Mammal.* According to Prof. Owen's description of the 

 placenta of the " Tatou," — a gerer.al term (or the Armadilloes — 

 this organ resembles, at least in general form, the discoid pla- 

 centiof an Inseclivore, while that of the Pangolin, described by 

 Huxley " Introduction to the Classification of Animals," p. gS), 

 after Sharpey, presents a third mode of organisation not le-s 

 distinct from the preceding. The Tamandua, in fine, thinks M. 

 Milne- Ed wards, offers an arrangement which, though differing 

 in some particulars from that existing in Cyclot/turus, seems to be 

 only an ex.aggeration. 



M. Milne-Edwards concludes by putting the pertinent question 

 — "are we to regard this diversity in the order Edentata as of 

 less importance than that accorded by naturalists to like 

 variations in the fcetal envelopes in other groups of the class 

 Mammalia? or are we to conclude that the different zoological 

 types included by zoologists under the name Edentata have less 

 affinity between them than is generally believed, and might be 

 represented in our system of classification by division of a higher 

 character." M. Milne-Edwards inclines — and in this we feel also 

 disposed to follow him — to the latter proposition, and proposes 

 at some future time to discuss and enlarge upon the same. 



J. C. G. 



METEOROLOGY 



On a Meteoric Iron lately found in El Dorado County, 



California \ 



For my knowledge of the meteoric iron of El Dorado Co., I 

 am indebted to Mr. Alfred Stebbins, librarian of the Mercantile 

 Library Association of San Francisco. A letter from him, dated 

 Aprd 26, inclosed a few grams of turnings obtained during the 

 separation of a slice of the mass destined for the collection ot the 

 geological survey now in progress under the direction of Prof. 

 Whitney. 



The mass is described by Mr. Stebbins as having the size and 

 shape of a man's head. It was found in a field, and, as usual, 

 was firat taken to a blacksmith's shop, where it was soon found 

 to be an unmanageable subject for working, and hence, fortunately, 

 found its way into scientitrc hands. Its surface possesses the in- 

 dentations common to these bodies — the crust or coating being 

 partially oxidised. It weighs eighty- five pounds. 



I find the turnings to have a specific gravity of 7 'So, which 

 may perhaps be a trifle above what the mass possesses, as it is 

 presumable that the turnings have suffered a slight condensation 

 in the process of separation. 



The fragments sent are free from all traces of sulphur. A single 

 analysis upon one gram has afforded me, 



Iron 8S '02 per cent. 



Nickel 8-8S 



Insoluble, consisting of a mixture of Fe^ 0;j 1 



and FeO, with minute silvery particles of > 3'So ,, 



supposed phosphor-metals (Scfireibersite) ) 



The amount of material at command was too small to search 

 for the other metals commonly found in meteoric irons. 



SCIENTIFIC SERIALS 



Le Mouilein- Scientijique, April, 1872. This number 

 commences with a translation of a paper by M. Mayer, 

 on alcoholic fermentation, and on the nutrition of the yeast 

 plant, and is followed by a long dissertation on scents, accord- 

 ing to recent discoveries in chemistry and physiology, by M. 

 Papillon. The next is a translation of a lecture by Dr. Ilofmann 

 on organic chemistry and therapeutics. The author points out 

 the numerous discoveries which have advanced the science of 



* Rapp seems to have made more out of Carus's plates than did M. Milne- 

 Edwards, for he states (Anatorncsette UiUcrsjtckjtngcn ilbcr die Edcniaten, 

 2^^ Aufl., p. 103. 1'iibingen, 1S32), that according to the said anatomist, 

 the placenta in this animal is made up of several cotyledons, which are from 

 half-an-inch to an inch in transverse measurement. 



t By Charles Upham Shepard, .Sen., Massachusetts, Professor of Natural 

 History in Amiierst College. Reprinted from the Amer. Jour. Science and Art. 



