September 4, 1885.] 



SCIENCE, 



185 



case of the Eoaring Eun and Apollo wells, it may be 

 possible that no porous stratum, which could serve 

 as a gas reservoir, was pierced by the drill: this, as 

 already stated {Science, July 17), is the first necessary 

 condition of the existence of gas. 



The Ridgway gas-well is located in a syncline, and 

 not on a subordinate anticline, as has been suggested, 

 but at a point where there is a certain regular dip of 

 about 1° toward the west, on the side of the syn- 

 cline. The Kane gas-wells — including the large one 

 at Kane, which is now supplying the residents of the 

 town with light and fuel, and the famous Kane 

 geyser (gas) well — are both in a syncline, the south- 

 east dip, in the one case, and the north-west dip, in 

 the otlier case, toward the centre of the basin, being 

 less than fifty feet per mile; and the south-west dip 

 along the axis of the basin being from fifteen to 

 twenty-five feet per mile. The great McMullen & 

 Hallet gas-well, commonly known as the ' Mullen 

 snorter,' is not in the vicinity of any anticline. _ The 

 gas-sand at this well is nearly horizontal, having a 

 dip of about eleven feet only in a direction S. 15° W. 



The gas-wells found in the vicinity of the city of 

 Erie are located in a region where no anticlines or 

 synclines have been discovered. The dip of the rocks 

 here is toward the south-west, at the rate of about 

 twenty feet per mile, from recent surveys : or from 

 the surveys made nearly fifty years ago, by the First 

 geological survey, as pointed out by Professor Lesley, 

 the average dip was estimated to be fourteen feet per 

 mile. Gas-wells have been drilled in the vicinity of 

 Fredonia, 'New York, one as early as 1821. Gas is 

 still obtained here; and, as far as the structure has 

 been made out, no anticlines exist in the vicinity of 

 the Fredonia wells. 



While these few facts would seem to be enough to 

 show that all gas-wells, either in the vicinity of pro- 

 ductive oil territory, or at considerable distances re- 

 moved therefrom, are not necessarily in the vicinity 

 of anticlines, many instances might be cited, partic- 

 ularly in the gas regions recently developed in Penn- 

 sylvania, to show that some of the largest and most 

 productive wells are either on or in the vicinity of 

 anticlinal crests. I am free to admit, as I have 

 already done, that the position of anticlines and syn- 

 clines have an important bearing upon the location 

 of profitable gas-wells ; but I cannot believe that, in 

 view of our present knowledge, the ' anticlinal theory ' 

 is suflQcient to account for all occurrences of natural 

 gas. As to whether it will be possible for facts still 

 to be recorded to give any geologist an adequate 

 basis for the formulation of an ultimate theory, we 

 must await the results of Mr. Carll's present investi- 

 gation. Chas. a. Ashbukneb, 



Geologist in charge Penn. surv. 



90" Walnut Street, Philadelphia, 

 Aug. 24. 



Annuaire geologique universel. 



The undersigned being mentioned, under the name 

 of Dr. Svedonius, amongst the collaborators in the 

 above-named work recently published by Dr. Dagin- 

 court in Paris, and two articles on Sweden and Nor- 

 way appearing in the same, signed in my name, of 

 which I had no knowledge until after their publica- 

 tion, I do hereby declare that the said articles are not 

 composed by me, but are uncritically compiled from 

 two pamphlets printed in the years 1874 and 1878, 

 and are, consequently, now substantially antiquated 

 pamphlets, with the authorship of which I had noth- 

 ing whatever to do. These pamphlets, together with 

 several others on the same subject, I have, at the re- 



quest of a Swedish man of science, forwarded to Dr. 

 Daglncourt, emphatically pointing out the time of 

 their publication ; and to this my collaboratorship in 

 the annual is restricted. 



Dr. F. Svexoxius, 



State geologist. 



Stockholm, July 31. 



Probable period of gestation in the 'horned 

 toad.' 



On the 15th of May last I captured a very fine 

 specimen of an adult female Phrynosoma Douglassii. 

 The fact having long been known to me that these 

 reptiles are capable of sustaining prolonged fasts 

 without any apparent inconvenience, I determined 

 to test the question for my own satisfaction and in- 

 formation. Accordingly, this specimen was placed 

 where it was impossible for it to secure any food. 

 One month after its incarceration it was taken out to 

 be examined. No particular change was noticeable; 

 the barest traces of emaciation could be seen in the 

 limbs ; but the creature upon being teased puffed it- 

 self up, as they do, and made short leaps with open 

 mouth at my finger. It also ran nimbly about my 

 study. 



It was replaced in its limited quarters, and an- 

 other month passed by without its having taken a 

 particle of nutriment. Its eyes now had a slight 

 sunken appearance, and some shrinkage of the limbs 

 could be detected. I dipped it in water for a moment, 

 and once more introduced it to its narrow prison. 

 At this stage of the proceedings my chief surprise 

 arose from the fact that the body of the animal still 

 retained its rotund contour, and was, if any thing, 

 plumper than at the time of the inauguration of the 

 experiment. 



Upon this date it had passed no excrementitious 

 matter for nearly three weeks. 



My surprise was great, when, in looking into the 

 box on the afternoon of the 10th of the present 

 month, to find strewed about the bottom of it no less 

 than seven newly-born young. These were all dead, 

 and enveloped in their membranes, which latter also 

 enclosed a bright yellow yelk about as large as a 

 small pea. At the time, circumstances prevented me 

 from making any further examination; but, two 

 hours later, my astonishment was at its pitch, when 

 I found fourteen more young had come to light. 

 Two of these were without the membranes and yelk, 

 but every one of the twenty-one was dead. 



Upon examining the mother, it was at once evi- 

 dent that her labor had not terminated; and, indeed, 

 within the next ten minutes she was delivered of 

 three more young ones. These were all born tail 

 first: two of them were living, and had to be simply 

 freed from their envelopes, the yelks having been 

 absorbed. The remaining one was like the majority 

 of the others, and lived but a moment or two. 



As I write these lines I have before me twenty- 

 two of the young in alcohol, two live and active 

 little fellows of the same brood, and the mother-liz- 

 ard, who, though she has lost much of her original 

 activity and flesh during her tJiree montJis' test, looks 

 for all the world as fully capable of enduring many 

 more days of it. 



Taking all the circumstances I have related into 

 consideration, I believe it will be found that about 

 one hundred days is the period of gestation of this 

 viviparous reptile. 



It will be of interest to state, in the present con- 

 nection, that other lizards endure these fasts as well 

 as Phrynosoma; for I have a large Sceloporus, uu- 



