March, 1915. 



KNOWLEDGE. 



89 



of the larvae are cIo?iely allied to Chinese white wax. In 

 addition to wax, the larvae of Phromnia marginella excrete 

 a sweet liquid, which hardens on the leaves. According to 

 Cotes, the natives (in Garawal) eat this stuff, and call the 

 insects " Dhaberi," which means sheep, the reference 

 being to their habit of clustering together, and jumping 

 away when disturbed. Dr. Imms gives a striking photo- 

 graph of the larvae covered with the white waxy filament. 



HABITATS OF NEJIATODE WORMS.— In a memoir 

 on freshwater Nematodes in North America Mr. N. A. Cobb 

 calls attention to the astounding variety in the habitats 

 of these threadworms. They occur in arid deserts, at 

 great depths, in hot springs, amidst polar ice, in the soil, in 

 fresh water, and in the sea. " As parasites of fishes, they 

 traverse the seas ; as parasites of birds they float across 

 continents and over high mountain ranges." They or their 

 ova are carried by wind and running water, by birds and 

 insects, or by almost anything that moves. One species 

 is almost restricted to the vermifonn appendix of man ; 

 another has its adult form only in grains of wheat ; a tfiird 

 has never been found, except in the felt mats on which 

 mugs of beer are set. ' ' The sour sap issuing from the wounds 

 of a tree, often many feet above the ground, not infrequently 



contains Nematodes that are specific to the wounds of that 

 particular kind of tree." 



Attention is also directed to some other points of much 

 interest. Thus eggs and larvae can survive prolonged 

 drought, and Mr. Cobb states that the revival of mummified 

 Nematodes may take place after as long a period as a quarter 

 of a century. Many are parasitic and harmful ; manv that 

 devour rotting material may help to clean things up ; and a 

 few are known to be actively advantageous, by feeding on 

 their injurious relatives and on baneful micro-organisms. 



Mr. Cobb refers also to their prolific multiplication — a 

 single female sometimes producing thousands of eggs and 

 to the huge numbers that may be found close together. 

 " A thimbleful of mud from the bottom of the ocean may 

 contain hundreds of specimens. The number of Nematodes 

 in the top six inches of an acre of ordinan*- arable soil 

 amounts to thousands of millions. Statistical calculations 

 relative to the number of Nematodes in a single acre of soil 

 near San Antonio, Texas, U.S.A., disclosed that if they could 

 start in a procession for Washington, D.C., two thousand 

 miles awaj', each close on the tail of the one in front, the 

 head of the procession would reach Washington before the 

 rear had left San Antonio." We have not verified this. 



SOLAR DISTURBANCES DURING JANUARY, 1915. 



By FRANK C. DENNETT. 



January proved to be a very unsatisfactory month for the 

 solar observer o^\^ng to the prevalence of cloud. No 

 observations were made by anv of the obser\'ers on 

 eight days (1st, 10th, 14th, 19th, 25th, 27th, 28th, and 30th). 

 On the 26th only taeniae were seen, but the disc never 

 appeared free from disturbance. The longitude of the 

 central meridian at noon on January 1st v.-as 91° 4'. 



No. 48 of the December list remained on the disc until 

 January 2nd, and therefore reappears on the present chart. 



No. 1. — This was first seen as a group of at least a dozen 

 spotlets and pores within the north-eastern limb on 

 January 2nd, and followed by a faculic ridge. By the 6th 

 there was a great leader with one larger and some small 

 umbrae twenty-nine thousand miles in greatest diameter, 

 and a trailer with Irwo umbrae fifteen thousand miles in 

 diameter. On the 8th the leader was enlarged by penumbral 

 extensions to thirty-two thousand miles. Both spots had 

 undergone considerable change by the 9th, and the large 

 spot was last seen close to the north-western limb on the 

 12th. The disturbance was eighty-six thousand miles in 

 length. 



No. 2.^Two pores were seen nearing the north-western 

 limb on the 4th, one remaining visible until the next day. 



No. 3. — A little group of three pores ; the larger leading 

 was seen on the 12th and 13th. It was not observed on 

 the 15th, probably owing to the constant passage of thin 

 cloud making observation difficult. On the 16th the area 

 was very facuhc, and contained several pores, closing up 

 to the south-western limb. 



No. 4. — A solitary spot, about 1° in diameter, was 

 observed from the 12th until the 23rd, On the 18th there 

 were two minute pores away to the south-west. 



No. 5. — On the 16th, when first seen, there was a group 

 of four pores ; but when last seen, on the next day, only the 

 trailer remained. 



No. 6. — A small spot was observed from the 16th until 

 the 21st, containing two umbrae and once accompanied by 

 a pore. 



No. 7. — A spot with two conspicuous umbrae, some 

 t\velve thousand miles across, was seen from the 16th 

 until the 24th, 



No. 8. — A pair of pores in a facuhc ridge near the north- 

 western limb was seen only on the 29th. 



No. 9. — A small spotlet with two pores on the south-west 

 was seen only on the 29th. 



No. 10. — A considerable spot round the south-eastern 

 limb was observed on January 31st, which broke into 

 a group, undergoing considerable metamorphosis, and was 

 last seen on February 6th. 



Faculae were observed near the north-western limb on 

 the 17th, 18th (311°, 26° N. ; and 298°, 19° N.), 24th, 26th 

 (185°, 13° N. ; 179°, 16° N. ; and 188°, 21° N.), 29th 

 (130°, 24° N.), and 31st. North-east on 2nd (following 

 No. 1), 22nd, 23rd, and 29th (close to the place of No. 1) ; 

 south-west on the 5th, 9th (60°, 25° S. ; 47°, 13°, and 17° S.). 



The chart is constructed from the combined observations 

 of Messrs J. McHarg, W. J. Waters, and the writer. 



DAY OF JANUARY, 1915. 



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