July 21, 1893.] 



SCIENCE. 



39 



of lactation. But few cows change one per cent from richest 

 milk of last month before drying up to thinnest milk after calv- 

 ing. 



The following is the record of six cows at the Experinoent Sta- 

 tion Farm that calved in the spring and were fed at the barn 

 heavily with grain, hay, and ensilage, before and during pastur- 

 age, and also after their return to the barn until they dried up. 



The influence of full feeding is seen most strongly during the 

 months of April and May, which yield, with grain, one-lhird 

 more milk and butter-fat than without. An influence after June 

 is seen, but not so pronounced. Those having grain shrink in 

 milk-flow only nine-tenths as fast as those not having grain, and 

 have the advantage of only one-trtenty-fifth in the shrinkage of 

 butter-fat. 



Of course, this is not a strict comparison of the effects of feed- 

 ing grain on the total yield or of the financial side of the que'stion, 

 but merely of the effect the grain has of increasing the flow of the 

 milk at once when the cow calves and of maintaining the milk-flow 

 for a longer period in the latter part of lactation. 



LETTERS TO THE EDITOR. 



..*** Correspondents are requested to be as brief as possible. Tfie writer's name 

 is in all cases required as proof of good faith. 



On request in advance^ one hundred copies of the nurfiber containing his 

 communication will be furnished free to any correspondent. 



The editor will be glad to publish any queries consonant with the character 

 of the journal. 



An Unusual Aurora. 



On Saturday evening, July 15, there occurred an aurora which 

 -w.is unlike any the writer has ever seen, and a brief description 

 of it may contribute something to the aggregate knowledge of 

 those interesting phenomena. 



The peculiar feature of this aurora was the movement of a series 

 or succession of whitish flecks across the sky from east to we.st, 

 a-ese milling somewhat the waves of a body of water. 



About 9.30, central time, my attention was first attracted to it. 

 Fiecks of white light were forming in the east at an altitude of 

 about 45°, passing in regular succession westward, about 80° north 

 of the zenith, and apparently accumulating in one larger band in 

 the northwest, reaching at times from near the horizon to perhaps 

 80". The white flecks or streaks were about 10° in length, strictly 

 parallel north and south, and quite uniform in distance apart. 

 They grew brighter and more distinct as they approached and 

 passed the meridian. Their motion was very regular snd quite 

 rapid, — comparable to the swiftest apparent motion of light 

 clouds. If they were as high as the electric theory would suggest, 

 the velocity must have been enormous. 



At times similar short bands, like strokes with a paint-brush, 

 were stationary in the north, at about 45° altitude, for several 

 minutes at a time. 



A few minutes later a number, perhaps ten or twelve, white 



bands appeared north of the zenith, all converging towards a 

 point some 10° south of the zenith, but vanishing before reaching 

 thezenith. They remained only a few minutes. About 10 o'clock 

 the moving flecks had disappeared, and one long, straight band 

 extended from the northwest horizon, 50° or 60°, toward a point 

 about 45° south of the zenith. Two or three other short flecks 

 appeared parallel with the main band. About the same time the 

 usual diffused glow appeared in the nortli horizon and continued 

 till after 11 o'clock, but was not observable while the moving 

 bands were seen. Many more gorgeous auroras have been seen in 

 our latitude, but the rapidly-moving bands gave this one a new 

 interest. W. H. Howard. 



Adrian, Mich. 



Light- Shunners and Light-Seekers. 



It is well known that in the main divisions of the animal world 

 we find groups which normally withdraw from daylight and 

 which form a very large minority of existing species Some of 

 these lovers of darkness dwell in caverns, in underground bur- 

 rows or in the seas at depths where the light penetrates feebly or 

 not at all. 



We might, perhaps, expect that such creatures would feel an- 

 noyed, more or less, by artificial light and would withdraw from 

 what to them must be an exceptional phenomenon. This, how- 

 ever, would be a mistake. The only nocturnal animals which 

 seem to shun fire and light are the carnivorous mammals espe- 

 cially the cats. It has long been customary for travellers in 

 Africa to keep lions, leopards, etc., aloof from an encampment 

 by means of bonfires. As a rule the sleepers are safe as long as 

 the fires are fed up. 



The lemurs and loris are even more nocturnal than the cats, 

 since they do not travel or prey by day. Whether they are re- 

 pelled or attracted by a light is not sufficiently decided. 



The bats are not purely nocturnal. They are sometimes seen 

 hawking for insects in full daylight. But a light attracts them. 

 Entomologists — I may mention Major Elwes, P. E. S. — who 

 have hung out lamps in order to entice moths, have often found 

 that bats come to the lights and secure a large share of the speci- 

 mens. 



Among birds there are few truly nocturnal species. The owl 

 and the night- jar (absurdly called the goat-sucker) are the most 

 common liight fliers. The owls are attracted by alight, a fact 

 which has given rise to a foolish superstition. They will often 

 dash against the window of a room which is lighted up by night. 

 If, as often happens to be the case, this is a sick-chamber, nurses 

 of^ the old school pronounce such a visit a fatal omen. Some 

 would-be wise men have gravely asserted that the owl scents the 

 approach of dissolution and comes in the hope of feasting upon 

 the corpse. Now, in fact, the owl feeds by preference on prey 

 which it has just killed, and in captivity it rejects any food 

 which is in the slightest degree tainted. 



In Australia the emur, though not truly nocturnal, may be 

 seen rapidly scudding over the plains by moonlight. 



Many birds which are perfectly diurnal, in their ordinary hab- 

 its, fly by night when migrating, and are then attracted by a 

 light. Numbers of various species dash themselves against the 

 windows of lighthouses and are killed by the shock. This is 

 much to be regretted, since the majority of migratory birds feed 

 on insects, and bad they survived they would during the coming 

 season have been hard at work ridding our crops of vermin. 



The habits of reptiles vary greatly. The few European snakes, 

 e.g., the viper, the asp, the Austrian .adder, the grass snake and 

 Coronella hevis, are rarely met with save in the brightest hours 

 of the day. But of the African, Indian and Australian species it 

 may be said : 



"The snake that loves the twilight has come out, beautiful, 

 still and deadly" — though they also bask in the sun. Nor are 

 they scared away by lights or fire. One species, indeed, if it 

 espies a fire in the forest, seeks to dash or drag the sticks away. 

 Toads, newts and salamanders live very contentedly in the dark, 

 but seem to regard a light with indifference. 



The majority of fishes and other dwellers in the waters are 

 decidedly attracted by lights. 



