January, 1913. 



KNOWLEDGE. 



27 



sinking far into the depths. This fact accounts for the 

 extreme rarity of many of these forms, for the ocean's surface 

 must have remained flat as a mirror for many hours before 

 they can be lured upward from the calm of their deep retreat. 

 Yet tender as they are to the touch, passing jelly-like between 

 the fingers of the hand that attempts to seize them, their food 

 consists largely of young fishes which they engulf in great 

 numbers, seizing their prey by means of their peculiar adhesive 

 cells. Thus, in the cold northern waters where ctenophores 

 occur in vast swarms, they constitute a serious menace to the 

 cod fisheries by devouring pelagic eggs and young fish." 



FIVE-YEAR PEDIGREED RACE OF PARAMOECIUM. 

 — Many facts seem to point to the conclusion that conjugation 

 or fertilisation in Protozoa renews the vigour of the cell-lineage. 

 Another view is that fertilisation is in some way concerned 

 with the phenomenon of variation, or that it may enable 

 the units to withstand changed environmental conditions. 

 Professor Lorande Loss Woodruff has devoted many years 

 to the experimental study of the slipper animalcule (Para 

 moecium), and one of his last papers is very interesting. 



On May 1st, 1907, he started with a " wild " Paramoecium 

 aurelia, isolated from an aquarium. When it had produced 

 four individuals by division, these were isolated to four lines. 

 The pedigreed culture has been maintained by a specimen 

 isolated from each of these lines practically every day up to 

 May 1st, 1912, thus precluding the possibility of conjugation 

 taking place and facilitating an accurate record of the number 

 of generations attained. 



In the five years there were three thousand and twenty-nine 



generations, four hundred and fifty two in the first, six 

 hundred and ninety in the second, six hundred and thirteen 

 in the third, six hundred and twelve in the fourth, and six 

 hundred and sixty-two in the fifth. The mean rate of division 

 was over three divisions in forty-eight hours. The organisms 

 were as healthy in 1912 as in 1907. They had given evidence 

 of the potentiality of producing a volume of protoplasm 

 approximately equal to lo 1000 times the volume of the 

 earth ! This seems to show that in favourable environment 

 there is no need of conjugation and no reason for senescence. 



FILOPLUMES. — It is usual to distinguish on a bird four 

 kinds of feathers, — the ordinary contours, the down -feathers, 

 the half-down, and the filoplumes. The last are most familar 

 on a plucked bird, standing up in scores on the bare body, 

 each like a hair with a tuft at the top. Very little is known 

 in regard to their development or their replacement, but Otto 

 Fehringer has recently described their arrangement in a 

 number of representative birds. They occur regularly along 

 with contour-feathers and occasionally with down feathers. 

 Their pits or follicles are separate from those of their com- 

 panion feathers, but closely juxtaposed. If contour-feathers 

 grow strong at one part of a feather-tract, so do the filoplumes. 

 On the main feather-tracts, the filoplumes occur in definite 

 relations to the contour-feathers. Thus, if the contour- 

 feather is median and directed backwards, it has a filoplume 

 on each side of its base ; if the contour-feather is lateral and 

 directed outwards and backwards, the filoplumes are on the 

 median side ; if the contour-feather is lateral, but directed 

 inwards and backwards, the filoplumes are on the lateral side. 



SOLAR DISTURBANCES DURING NOVEMBER, 1912. 

 By FRANK C. DENNETT. 



November has proved very unfavourable to the solar observer. 

 Six days were too cloudy to admit of observation, and some 

 others were too dull to yieid very satisfactory results. The 

 disc was apparently clear of disturbances, bright or dark, on 

 thirteen days, and on eight only faculae were visible. At noon 

 on November the 1st, the longitude of the central meridian 

 was 90° 3'. 



No. 23. — The only spot disturbance seen was first recorded 

 on the 17th, the Sun not having been visible on the two 

 previous days. At 10.45 a.m. it was described as a small 

 very black spot having little penumbra, but followed by an 

 elliptical faculic disturbance containing at least eight pores. 

 A little after noon the edge of the umbra was observed to be 

 frayed, and at the other side of the faculae were indications of 

 a trailer or end spot. Directly eastward of the leader a dark 

 hydrogen floculus was visible with the spectroscope, pointing 

 towards the S.S.E., deflecting the C.-line towards red. On the 

 18th the group seemed little altered and when last seen, on 

 the 19th, there appeared to be two spots, one at each end, 



but clouds intervened before measures could be completed. 



On November the 30th there was apparently a badly-formed 

 spot in the equatorial region near longitude 95°, with traces of 

 •pores in a rough-looking area by which it was surrounded. 

 No measures were obtained. It was doubtless the remains of 

 the disturbance which produced the groups of Nos. 18 and 20. 



Faculic disturbances near longitude 10°, S. latitude 6° to 

 10°, were observed within the eastern limb, on November 1, 2, 

 3, and 29, and approaching the western edge on the 11th. 

 The faculic area connected with the spot group 23, was seen 

 as it approached the western limb on the 25th and 26th. 



In the preparation of this little note the importance of com- 

 bined study by observers at distant stations cannot be over- 

 estimated. Six observers at five stations so far separated as 

 Lisburn, Manchester, Bath, Margate and Hackney, the 

 greatest number of observations at any one station being 

 eighteen. The observers were Messrs. J. McHarg, A. A. 

 Buss, C. Frooms, E. E. Peacock, W. H. Izzard, and the 

 writer. 



DAY OF NOVEMBER, 1912. 



