92 Chronicles of Science. [Jan., 



of Juno ; Encke from the perturbations of Yesta found the value 

 — — - , and from the perturbations of the comet bearing his name, 

 -jr=j. Gauss confirmed these results by observations of Pallas. Airy, 

 returning to the satelhtes, obtained the value in 1837 ; a 



result confirmed by Bessel's determination, ^ , and by Captain 



Jacob's estimate, 2 ^. — both these results being also deduced 



from observations of the satellites. Herr Kruger's estimate, obtained 

 from a series of most careful investigations of Themis (one of the 



minor planets) gives . The mean of the four last-named 



values 1 1047 . 34 J may safely be accepted as a very close approxi- 

 mation to the true mass of the largest planet of the solar system. 

 It is to be expected that the influence of Jupiter on Saturn, which 

 seemed to Bouvard (before the discovery of Neptune) to indicate a 



mass of j^=jr, will be satisfactorily accounted for by the value now 



assigned to Jupiter's mass. 



The variable in Corona, whose appearance (sudden, we think, 

 despite Mr. Hind's verdict) startled astronomers in May, and which 

 had sunk to the 9th magnitude, increased in "brightness to the 7th 

 magnitude} towards the end of August last ; but Mr. Huggins's 

 spectroscope revealed no traces of the bright lines which in May 

 formed so marked a feature of the star's spectrum. The star has 

 now returned to the 9th magnitude. 



4. BOTANY AND VEGETABLE PHYSIOLOGY. 



England. — Homologies of the Flowers of Conifer as. — Mr. Andrew 

 Murray has published an interesting paper on this subject, in which, 

 at some length, he demonstrates that the male flowers are 

 monopetalous and diandrous in the firs and pines, monopetalous 

 and polyandrous in the cypresses and allied genera. The 

 female flower is also monopetalous. In the young state, the 

 petal is a small bract, sometimes green, sometimes even more richly 

 coloured than the petal of the male flower, always petaloid in 

 texture, at least at the margins. The author supposes^ the 

 envelopes to have the following homologies : — 1. Outermost envelope, 

 or its appendage, corresponds to, in ordinary dicotyledons, the petal ; 

 in conifers, to the bract. 2. Next envelope corresponds ordinarily 

 to the disk ; in conifers, to the scale. 3. First covering of the fruit, 

 ordinarily the pericarp ; in conifers, the wing of the seed. 4. 



