48 



KNOWLEDGE. 



Table 12. Occultations of Stars by the Moon visible at Greenwich. 



February, 1915. 



From New Moon to Full disappearances occur at the Dark Limb, from Full to New reappearances. 



Eastern elongations of Tethys (every 4th given) S** y*" -7 m, 

 10^ S^-g?, ISMO^-a m, 25*' ll''-5 e; of Dione (every 3rd 

 given) S-" 10'^ -1 m, le*" 3"" -3 e, 24"* S''-4 e ; of Rhea (every 

 2nd given) T^ 11'' -1 iit, le'' Noon, 25^ l^-O e. 



For Titan and Japetus E., W. stand for East and West 

 elongations, I. for Inferior (North) conjunction, S. for Superior 

 (South) conjunction. Titan 4'* e'' -8 m S., S"* 9^ -1 m E., 

 12'' Qi^ -1 m I., le'i 6*' -3 m W., 20<' 6^ -0 m S., 24^ 8'' -5 m 

 E., 28'' 8''-5 m I.; Japetus 1'' 2^ m W., 20'' 1^ m S. 



Uranus is invisible. In conjunction with Sun on February 

 1st. 



Neptune was in opposition January 20th, diameter 2". 



Double Stars and Clusters. — The tables of these, 

 given three years ago, are again available, and readers are 

 referred to the corresponding tnonth of three years ago. 



Variable Stars. — Stars reaching their maxima in or near 

 March, 1915, are included. The lists in recent months may 

 also be consulted. 



Meteor Showers (from Mr. Denning's List) : — 



Table 13. Long-period Variable Stars. 



Night Minima of Algol I'' 7" -26, 4" 4" -Oc, Id" 3" •4m, 19" O'' -1 m, 21'' 8" ■ 

 Principal Minima of (3 Lyrae March l" b^e, 14" A^e, 27" 3"" c. 



9 e, 24" 5" -7 e. Period 2" 20'" 48'° -9. 

 Period 12" 21" 47"-5. 



REGENERATION. 



The regeneration of " arms " in starfish, claws in lobsters, 

 and tails in lizards exemplifies the replacement of lost 

 parts in animals ; and, although we cannot get a new lizard 

 from an old tail, or a new lobster from a discarded claw, yet 

 it is possible to grow a new starfish from a detached arm. 

 In the vegetable kingdom this kind of regeneration is more 

 common, and is put to practical uses. The making of 

 a cutting may not seem so striking as the growing of 

 a new starfish, for roots only have to be formed (see 

 Figure 40), and this underground ; but many leaves can 



produce, not one young plant, but quite a number. This 

 is the case in Bryophvllum, and in Figures 35 and 36 a leaf 

 is shown which has been lying on the moist ground for a 

 little time. The edges of it are bounded by quite a clump 

 of young plants. Figures 36 to 39 show other leaves, 

 which will reproduce the whole plant, and the begonia is 

 commonly propagated by gardeners in this way. Figures 

 40 to 49 also bear on this question, and it is possible to 



obtain a geranium from a leaf-stalk. 



W. M. W. 



