Makch 12, 1897.] 



SCIENCE. 



447 



required to take twelve half-days' instruction in 

 the details of the course in experimental physi- 

 ology, before October 1st of their year of service. 



No charge of any kind will be made for the 

 year's training. 



The Harvard Medical School will give suc- 

 cessful applicants the title of ' Assistant in 

 Physiology,' and for the direction of the classes 

 in experimental physiology will pay each As- 

 sistant four hundred dollars. 



Applications may be sent to 



Professor H. P. Bowditch. 



Haevaed Medical School, Boston, Mass. 



note on nateix geohamii b. & G. 



In Professor O. P. Hays' report on the Batra- 

 chians and Reptiles of Indiana* he says, on p. 

 589, "The young are no doubt brought forth 

 alive and active." There is now no question 

 about the fact of their being viviparous, as 

 several were born alive in the Chicago Academy 

 of Sciences, July 29th. 



The adult female, measuring 775 mm. in 

 length, was collected at Glenn Ellyn, Illinois, 

 on July 25th, by Mr. Frank M. Woodruff, and 

 its extreme size was particularly noted; four 

 days later it gave birth to eight young, which 

 were alive and very active. The births took 

 place some time during the night, and the 

 young were noticed on the following morning a 

 little after 7 o'clock. They were at that time 

 fully active and resembled somewhat the parent, 

 although differing in some of the color mark- 

 ings. The young measured 246 mm. in length 

 and were colored as follows: Back 'slaty-blue 

 with two very dark dorsal stripes; a dark stripe 

 borders the edge of the blue dorsal surface and 

 separates it from the yellowish lateral surface; 

 this is in turn separated from the greenish- 

 yellow ventral surface by a black stripe, which 

 follows the edges of the plates in a zigzag man- 

 ner and disappears on the side of the head. 



The young were kept alive for several weeks 

 and finally preserved, with the parent, in the 

 Academy's collection (Mus. No. 10,337 adult; 

 10,335 young). As another point of interest 

 we might mention that a specimen of the West- 

 ern Bull Snake (Pitnophis sayi Schleg), measur- 



* Indiana. Department ot Geology and Natural 

 Eesources, 17th Annual Report, 1891. 



ing nine feet in length, laid twenty-two eggs in 

 captivity during the first week in August. The 

 female was in the same cage with a small male 

 for about two months previous to the laying, 

 and it is probable that copulation took place 

 during captivity. 



Frank C. Bakee, 

 Frank M. Woodruff. 



pseudo-aueoea again. 



In Science, First Series, for December 2 and 

 16, 1892, there was a short discussion of this 

 subject, and now appears a still longer letter on 

 the same subject in Science for January 29, 

 1897. It seems a little strange that so simple a 

 phenomenon should give rise to so diverse views, 

 and yet when we consider how many views have 

 been given of a''precisely similar phenomenon, 

 'The Brooken Spectre,' it is not so surprising. 

 It is probable that this latest description is 

 given from memory and not from notes made 

 at the time — an exceedingly important proceed- 

 ing if one would keep from falling into grievous 

 errors. Every electric arc light has a support 

 at the top, and this would absolutely prevent 

 any column of pure white light being projected 

 toward the zenith. More than this, if these as- 

 sumed horizontal planes of ice reflected the 

 light it seems impossible to consider that the 

 reflections would be only from a region directly 

 above the lamp. 



If one will turn to the description in Science, 

 December 2, 1892, he will see how it is almost 

 exactly contrary to this later one, and yet the 

 former undoubtedly presents a better idea of 

 the phenomenon. When the air is full of frost 

 particles or fog any object standing before a 

 light will cast a shadow into the mass of frost 

 particles or fog. If one will stand underneath 

 an arc light when the air has fog in it he will 

 see what appears like a beam projected into the 

 fog. The same may also be seen when any foot 

 rest or projecting arm intercepts the light; in 

 this case a horizontal beam will be seen passing 

 into the fog. Just at sunset if one stands upon 

 a broad plain with his back to the sun he will 

 see his shadow cast upon the ground and ex- 

 tending more than 100 feet to the eastward. 

 Now imagine the surface on which the shadows 

 cast to be practically on all sides like fog ; then 



